- Greenhouse Tomato Plant Care: Tips For Growing Tomatoes In A Greenhouse
- About Greenhouse Tomatoes
- How to Grow Tomatoes in a Greenhouse
- Greenhouse Tomato Plant Care
- How to Grow Tomatoes
- How do you grow tomatoes from seed?
- What variety of tomato should you choose?
- How much water do tomato plants need?
- How do you grow tomatoes in a greenhouse?
- How do you grow tomatoes outside?
- How do you train tomato plants?
- When should you harvest tomatoes?
- Common problems with tomato plants
- Connect With Us!
- 1. You Planted The Wrong Varieties
- 2. You Planted Tomatoes Too Close Together
- 3. You Aren’t Practicing Crop Rotation
- 4. You’re Not Watering Consistently
- Is it a fruit or a vegetable?
- Choose the type of tomatoes you want to grow in your greenhouse
- How to set up your greenhouse for your tomatoes
- How to grow tomatoes in a greenhouse
- Recommended Tomato Greenhouse: Arcus
- Pests and disease control
- Water your tomatoes properly
- Harvesting your tomatoes
- How to properly store tomatoes
- January 2001 Thinking About Greenhouse Tomatoes? By Rick Snyder
- Scientists Discover Why Most Tomatoes Taste Awful—And How To Fix It
- Hothouse Tomatoes Pack Summer Flavor in the Springtime
- Indoor Tomatoes 101
- Carrying On a Greenhouse Legacy
- Extending the Season
- Old Habits Are Hard to Quit
- How to Grow Your Own Tomatoes, Part 1: Starting Seeds Indoors
- Time and Place
- Tomato Woo-Woo
- Growing Tomatoes in a Greenhouse
- When to Plant Tomatoes in Your Greenhouse
- Growing Tomatoes from Seeds
- Growing Tomatoes in Pots
- Growing Tomatoes in Grow Bags
- Some Great Greenhouses to Grow Tomatoes in.
- Cordon Tomatoes
- Stopping Tomatoes
- Feeding Your Tomatoes
- Watering Your Tomatoes
- Tomato Diseases and Pests
- How to grow tomatoes
- Great tomato varieties to grow
- Growing Tomatoes Anytime in the Greenhouse
- Trial Criteria for Johnny’s GREENHOUSE VARIETIES
Greenhouse Tomato Plant Care: Tips For Growing Tomatoes In A Greenhouse
We have to have our tomatoes, thus the greenhouse tomato industry was born. Until fairly recently, this favorite fruit was either imported from growers in Mexico or produced as greenhouse tomatoes in California or Arizona. Growing tomatoes in a greenhouse isn’t for the faint of heart; they require specific greenhouse tomato plant care entirely different from other crops. If you’re interested in trying your hand, read on to learn how to grow tomatoes in a greenhouse.
About Greenhouse Tomatoes
Growing tomatoes in a greenhouse is a great way to extend the season either due to a short growing season in your region or because you’d like to get a second crop. In some regions, the window of opportunity for cultivating tomatoes is short and folks are left pining for vine ripened tomatoes. This is where the beauty of greenhouse grown tomatoes comes into play.
Growing tomatoes in a greenhouse or high tunnel can extend the harvest season by several months up into late fall but that isn’t the only benefit. It also shields them from rain which can facilitate fungal disease.
Commercial greenhouse tomato growers go to great lengths and expense to manage their crop. Most use hydroponics, although some are grown traditionally in soil. Most are managed organically without the use of pesticides or synthetic fertilizers. Also, because the plants are grown indoors, they need some help with pollination. Some growers bring in bumblebees, while others vibrate the plants manually to move the pollen to its receptor.
Home growers can try to mimic these conditions too, but it does take a bit of an investment and some serious commitment, but hey, a longer tomato season makes it all worthwhile!
How to Grow Tomatoes in a Greenhouse
First of all, to produce fruit, the temperature of the greenhouse should be 60-65 F. (15-18 C.) at night and 70-80 F. (21-27 C.) during the day. This may require cooling of the greenhouse during the day, or warming at night depending upon your region.
Air circulation is also important and is provided by exhaust fans as well as proper spacing of the plants. Circulation helps maintain a constant humidity level and reduces the incidence of disease.
To get the maximum number of tomatoes and really extend the growing season, plan on planting on a two-crop rotation. This means that a fall crop is seeded in early July or by early June and a spring crop is seeded in December to mid-January.
Usually there’s about 36 inches (91 cm.) of work space between pairs of tomato rows that are spaced 28-30 inches (71-76 cm.) apart.
Transplants should be planted in moist soil so the stem is covered a half inch or so above the previous soil line. Before the plants are a foot tall, have some sort of trellis system in place. Usually, this involves plastic twine tied from the plant to a heavy gauge wire support suspended above the row.
Greenhouse Tomato Plant Care
Train the tomatoes by removing all wide shoots as soon as they develop in the axils of the leaves, usually each week.
Commercial tomato growers may use electric vibrators, electric toothbrushes, and mist blowers, knocking the support wires or other automatic shakers to distribute pollen. Depending upon how many tomatoes you plan on growing, hand pollinating with a simple transfer of pollen with a very light brush or cotton swab will suffice. It may be somewhat time consuming, but without transfer of the pollen from the anthers to the stigma, there will be no fruit. Pollinate every other day.
As fruit is produced, thin to 4-5 fruit per plant when they are small. Remove lower leaves to facilitate air circulation and reduce the incidence of disease.
Be sure to give the plants plenty of water. Start either weekly sprays or biological controls the moment the plants are in the greenhouse to get a jump on potential problems.
And, lastly, keep meticulous records with complete dates, the name of the cultivars as well as any other special considerations.
How to Grow Tomatoes
Tomatoes are an easy, satisfying crop
Image: / StockCreations
You can’t beat the flavour of home-grown tomatoes straight from the vine – and they’re so easy to grow! Simply choose your favourites from the huge range of tomato seeds and tomato plants on offer, and follow our instructions to make sure you enjoy a bountiful and succulent, sun-drenched harvest.
How do you grow tomatoes from seed?
To get them ready for the summer salads, sow your seeds in March or April
Image: / FotoDuets
Sow your tomato seeds in March or April, approximately 6-8 weeks before the final frost of the winter, or earlier if you’re growing your tomatoes in a greenhouse. Sprinkle the seed thinly onto good quality seed compost. Cover with 1.5mm of compost and water lightly with a fine-rose watering can.
If you’re only growing a few plants, sow two seeds into a 7.5cm (3″) pot. Keep the compost moist, but be careful not to over-water as wet conditions can encourage “damping-off” disease, and other mould problems. At a temperature of 21 degrees celsius, tomato seeds usually germinate in 7 to 14 days. After germination remove the smaller plant.
Pot on the tomato seedlings as soon as they’re big enough to handle. Hold the plants by the leaves, taking care not to touch the stems, and transplant them into 7.5cm (3in) pots. Protect the plants from frost, cold winds, and draughts which might kill them.
What variety of tomato should you choose?
|Cherry Tomatoes||Plum Tomatoes||Heirloom Tomatoes||Medium (‘Normal’) Tomatoes||Beefsteak Tomato|
|Tomato Gardener’s Delight||Tomato ‘Il San Marzano Lungo’||Tomato Brandywine||Tomato Ferline||Tomato Super Marmande|
|Tomato Gartenperle||Tomato Roma VF||Tomato Craigella||Tomato Cristal||Tomato Country Taste|
|Tomato Maskotka||Tomato Falcorosso||Tomato Yellow Stuffer||Tomato Tamina||Tomato Cuore di Bue|
|Tomato Losetto||Tomato Principe Borghese||Tomato Black Russian||Tomato Orkado||Tomato Striped Stuffer|
|Tomato Suncherry Premium||Tomato Roma Nano||Tomato The Amateur||Tomato Alicante||Tomato Big Daddy|
If you’re still undecided, take a look at our tomato selector guide to help you choose which tomato varieties to grow.
How much water do tomato plants need?
To produce a bountiful crop, tomatoes need regular and plentiful watering
Image: / Fotokostic
Tomato plants need a lot of water and feed if they’re to produce a bountiful crop. For best results, water little and often. Some gardeners leave a few filled watering cans to warm in their greenhouse so the water is not shockingly cold from the tap or water butt.
Some people claim that watering at exactly the same time each day makes a difference to the quality of the crop! Feed your tomatoes with a general liquid feed until the first truss has formed then alternate with a high potash feed to encourage more flowers and fruit.
How do you grow tomatoes in a greenhouse?
Varieties like the Moneymaker tomato thrive in greenhouses
Image: Thompson & Morgan
Growing tomatoes indoors produces an early crop, especially if you choose recommended varieties like ‘Sungold’, ‘Money Maker’ or ‘Country Taste’. If you’re after tomatoes to make soups and sauces then tomato ‘Roma VF’ is the variety for you. Sow in 7.5cm (3″) pots from February onwards, according to the instructions on the seed packet.
Plant the young plants when they are about 15-20cm (6-8in) tall and the flowers of the first truss are just beginning to open. If you’re planting into your greenhouse border, make sure you dig in plenty of garden compost or well-rotted manure during the winter, and do remember to rake in a general purpose fertiliser before planting.
If you’ve used your borders for tomatoes before, it’s best to change the soil before growing them again, or soil pests and root diseases can be a problem. Growing tomatoes in pots or a grow bag? Remember they’ll need a lot more water and care.
Plant your tomatoes about 45cm (18in) apart, leaving 75cm (30in) between rows, and if you’re planting into a grow bag, limit yourself to two plants per bag. Tomatoes prefer a temperature of 21 – 24C (70 – 75F) and will perform poorly at temperatures above 27C (81F) or below 16C (61F). Make sure you ventilate the greenhouse regularly to deter pests and diseases.
How do you grow tomatoes outside?
When using hanging baskets, use tomatoes that are known to flourish outdoors, like âGardener’s Delight’
Image: Thompson & Morgan
For best results, choose trusted favourites like ‘Gardener’s Delight’, ‘Money Maker’ or ‘Sweet Olive’. Alternatively if you’re growing your tomatoes in hanging baskets, go for varieties like ‘Cherry Cascade’ or ‘Tasty Tumbler’.
Wait until approximately 6-8 weeks before the last frost is forecast and sow as directed on the seed packet in 7.5cm (3in) pots. It’s time to plant out the young vines when they’re about 15-20cm (6-8in) tall, the flowers of the first truss are just beginning to open, and the risk of frost has passed.
If you’re planting into the ground, make sure you dig in plenty of garden compost or manure during the winter, and just before planting, rake in a general purpose fertiliser. Tomatoes are hungry plants!
Plant your tomatoes about 45cm (18 in) apart, leaving 75cm (30in) between the rows. If you’re growing them in grow bags, limit the number of plants to two, and do remember they’ll need extra watering and care.
To save space, grow your outdoor tomatoes in hanging baskets, or upside down. Simply plant a young tomato plant through a hole in the bottom of a bucket or similar hanging container, and fill the container with multi-purpose compost. Suspend the bucket from a bracket and allow the plant to dangle beneath it.
How do you train tomato plants?
To ensure healthy tomato growth, training them to rely on a support is crucial
Image: / itakefotos4u
How you train your tomato vines depends whether you opt for cordon/indeterminate, semi-determinate, or determinate varieties:
- Cordon/indeterminate: The most common tomatoes, these single stemmed plants with the side shoots removed grow very tall, sometimes reaching 2.5m.
- Semi-determinate: Similar to indeterminate varieties (grown as cordons) but producing shorter plants.
- Bush/Determinate: Stop growing sooner than indeterminate varieties with the stem ending in a fruit truss. They are referred to as ‘bush’ and ‘dwarf’ types, and are suitable for hanging baskets. They don’t require any pruning.
With indeterminate and semi-determinate varieties (cordons), tie the plant to a support as it grows. Pinching out the side shoots as they develop concentrates the plant’s energy into producing fruit. When the cordon reaches the top of its support, cut out the tip of the main stem two leaves above the top flower truss.
For the best quality fruit it’s best to limit the number of fruit trusses to six per plant. If the vine doesn’t reach the top of its support by late summer, cut out the main tip anyway to give the remaining fruits time to ripen.
Determinate varieties (bush/dwarf types) don’t need pruning or training and happily sprawl along the ground or around the pot they’re growing in. Determinate varieties can stop flower production after several trusses, but you can encourage continued upward growth by training up the topmost side shoot.
When should you harvest tomatoes?
The yummiest part of planting and growing tomatoes is definitely the harvesting
Image: / goodmoments
Start picking your tomatoes as the fruits ripen and gain full colour. When frost threatens at the end of the season, lift any plants with unripe fruit on them and hang them upside down under cover. Tomatoes can be successfully frozen if you find you have a glut.
Common problems with tomato plants
Like potatoes, tomatoes get blight. Make sure you take the right precautions when growing
Image: / Radovan1
A common problem caused by wet weather, particularly with outdoor plants, tomato blight spreads fast, leaving telltale brown patches all over the plant. Not only does blight kill vines, it also rots the fruit. How to stop blight? Grow blight resistant tomato varieties or spray Bordeaux Mixture on your plants early in the summer.
Irregular watering, or too much water too late in the growth cycle causes fruiting problems like:
- Blossom End Rot: Dark patch at the base of the fruit, more common if the plant is grown in a grow bag.
- Blossom Drop: Flower bud falls off.
- Dry Set: Fruitlet growth stops when the fruit is the size of a match head.
- Splitting fruit
The key to a healthy crop of tomatoes is regular, even watering, delivered to the base of the plant. Too much water too late tends to be the problem in most cases, especially with plants grown in pots and grow bags.
Too much direct sunlight can also damage your crop. Tomatoes need high light intensity to grow well, but too much can cause blotches, scalds or spots on the developing fruit. ‘Greenback’ is a common problem caused by too much sunlight, leaving the ripe fruit with a hard green area on its ‘shoulder’.
If this is a problem increase the potassium in your plants’ feeding regime and use fleece or shading as a cover in the hottest part of the day. It may also help to use resistant varieties like ‘Alicante’ or ‘Craigella’.
Consider companion planting marigolds with tomatoes as a whitefly repellent
Image: / Swellphotography
Look out for green and white fly because both can spread viruses. Spray your vines with a recommended insecticide as soon as you notice pests. Organic gardeners might prefer to plant marigold varieties like ‘Tomato Growing Secret’ nearby which attract beneficial insects that eat pests.
Keep an eye on your leaves; these could reveal ill health for your tomatoes
Image: / Jean Faucett
Curling leaves. May be caused by aphids sucking the sap from them, but if there’s no sign of insects the most likely culprit is cold night-time temperatures (more noticeable in early summer). If this is the case, it’s nothing to worry about.
Mosaic patterns, streaks or distorted leaf surfaces. Your tomatoes may have a virus, in which case your best bet is to remove and destroy them before the problem spreads. Always disinfect tools, boots, and gloves after handling diseased plants.
Leaf yellowing starting on older leaves and moving upwards. The problem could be a magnesium deficiency which is easy to remedy with a special magnesium feed.
For a visual tomato growing guide, check out this ‘How to grow tomato seeds video.
Growing tomatoes is such a satisfying way to get ingredients for your soups, salads, sandwiches and more. If you’ve never tried, give it a go – and if you’re a seasoned hand, which new varieties should you try?
Connect With Us!
PHOTO: USDA/Flickrby Lisa Munniksma October 20, 2015
Tomatoes are one of the top-three consumed vegetables in the U.S. It’s no wonder they’re a favorite of farmers and gardeners, too. This heat-loving crop can be grown year-round in many parts of the country if you treat them right in season-extending structures, like greenhouses, hoop houses and high tunnels. By pampering these fickle plants with indoor growing spaces, you have to be careful to treat them properly. Tomatoes are susceptible to mineral deficiencies, fungal and bacterial diseases, insect pests, and problems related to watering.
If you’re wondering why your greenhouse tomatoes aren’t up to par with the tomatoes you grow in the garden, you might be making one of these four common mistakes.
1. You Planted The Wrong Varieties
Who doesn’t love a fat, funny-looking heirloom tomato? A farmer’s desire for the first Brandywine tomato of the year may lead him to plant a row of Rose in the high tunnel, but many heirloom tomatoes don’t do very well in an enclosed environment, leading to plant-health issues.
“Varieties bred for the greenhouse environment need to be used, rather than field- or garden-type tomatoes,” according to Rick Snyder, PhD, of Mississippi State University Extension Service. “All varieties are indeterminate so that they can produce over a long harvest season.”
Instead, Try: Snyder says the most widely used variety in the U.S. is the Dutch hybrid Beefsteak-type tomato Trust. If you’re after heirloom-like tomato varieties for the greenhouse, Johnny’s Selected Seeds suggests the hybrids Marnero (similar to Cherokee Purple) and Margold (imitates Striped Germans).
2. You Planted Tomatoes Too Close Together
mystuart (on and off)/Flickr
Because tomato plants are subject to foliar diseases like Botrytis blight (aka gray mold), early blight and leaf spot, they require air movement. You might notice fuzzy mold patches forming on living and dead plant tissue, yellowing leaves, girdled stems and dying plants. Greenhouses and high tunnels need to have good ventilation because as humidity builds up, so does the opportunity for these issues to take hold.
Instead, Try: According to Snyder’s “Greenhouse Tomato Handbook,” greenhouse tomatoes need at least 4 square feet per plant. Planting double rows with plants 4 or 5 feet apart (from center to center) is an efficient use of coveted indoor growing space.
This formula determines how many tomato plants you should be growing in your greenhouse:
Multiply the length of the greenhouse in feet by the width.
Divide by 4 (to space every 4 square feet) or 5 (to space every 5 square feet).
The answer is the number of plants you should put in this structure.
Planting at 4 square feet or 5 square feet should give about the same yield overall, as putting them closer together will shade some of the plants (you’ll see plants getting very long and tall) and invite diseases. Having more plants, though, means more labor for planting and trimming.
Keep plants suckered; trim any foliage below branches that are bearing fruit; and trim yellowing, dead or diseased plant tissue and fruit to improve air circulation and reduce crowding. Discard these materials outside of the greenhouse to prevent them from causing further problems to the plants that are still growing and producing.
3. You Aren’t Practicing Crop Rotation
Putting plants in a greenhouse doesn’t get you off the hook of having to rotate families of crops. If anything, the closed-in space makes rotation that much more important. After growing tomatoes year after year in the same space, you might notice uneven ripening due to low soil nutrients, increased pest pressure, recurring diseases, a fungus you just can’t kick or overall lack of productivity in your tomato crop.
Instead, Try: If you have more than one greenhouse, high tunnel or hoop house, grow your nightshade plants (tomatoes, peppers, eggplant, et cetera) in a different one each year. If you have only one season-extending space to work with, pay close attention to adding the right soil amendments (get a soil test each year), maintain proper pH, be vigilant about staying on top of pests and diseases throughout the season, and solarize the structure in the off-season to kill diseases and pests that could be hanging out in the soil.
Snyder cautions against growing different crops in the same greenhouse at the same time, as each has its own growth requirements that you might not be able to manage under one roof.
“You could, however, grow a main crop, like tomatoes, and have a ‘few’ of something else, just to try out,” he suggests. “But, in that case, the system should be optimized for the main crop.”
4. You’re Not Watering Consistently
It’s exciting to watch tomatoes get really big while ripening on the vine, and it’s disappointing to harvest them and find the bottom has cracked or has turned black from blossom-end rot. Likewise, it’s frustrating to see your tomato plants wilting in the greenhouse—looking dull and feeling rubbery—or to find rows of beautiful tomato flowers but no fruits forming. Snyder finds these symptoms may be the fault of inconsistent watering.
Instead, Try: Snyder says full-sized tomato plants require 2 to 3 quarts of water each per day when it’s sunny, and this water needs to be delivered at regular intervals.
“Many growers water as often as once every 30 or 60 minutes in hot climates,” he points out.
Unlike growing tomatoes in the field, where Mother Nature is in charge, you have complete control over irrigation in the greenhouse, whether you turn on and off a drip-irrigation system yourself or you have one set on a timer. (Don’t use overhead irrigation for tomatoes, as the leaves are sensitive to disease caused by contact with water or with soil that’s splashed onto them as a result of watering.)
These four issues are just the start to mistakes commonly made when growing tomatoes in a greenhouse, hoop house or high tunnel. You can really brush up on your greenhouse-tomato game with help from your local cooperative extension office or at Snyder’s annual Mississippi State University Cooperative Extension Greenhouse Tomato Short Course, which takes place each year in March for tomato growers from across the country.
A tomato is a gardeners’ cream of the crop. If you had tomatoes from a garden before, you cannot deny that store-bought ones cannot keep up with those from a garden. If you love them as much as we do, you may be wondering how to grow tomatoes in a greenhouse.
Tomato is a popular greenhouse crop that provides an excellent harvest. The tropical and humid condition of your greenhouse is ideal for planting tomatoes. With good lighting and proper temperature control in your greenhouse kit, you can easily have multiple harvests yearly. Note that proper handling of these greenhouse conditions facilitates two of the most important processes: successful pollination and disease prevention.
Is it a fruit or a vegetable?
The tomato is one of the top five most consumed fruits. Or vegetables? You might be wondering as well what could it be. Did you know that the U.S. Supreme Court ordained in 1893 that tomatoes are vegetables notwithstanding the botanical evidence that they are carefully considered as fruits?
However, according to the United States Department of Agriculture, tomatoes are considered fruits while nutritionists and the horticulture trade consider them as vegetables. The word “fruit” is used to represent sugary and fleshy while “vegetable” means that it doesn’t have a very high fructose level. However, botanically speaking, a tomato is unquestionably a fruit. So technically a tomato is the fruit of a tomato plant, and it is used as a vegetable in culinary perspectives.
Choose the type of tomatoes you want to grow in your greenhouse
There are diverse varieties of tomatoes. They have its individual unique grown fruit, taste and culinary purpose. Let’s have a look at these:
Cherry tomatoes are the smallest and sweetest variety. They are ideal for salads and pasta recipes.
Plum tomatoes are fleshy usually have fewer seeds and excellent for appetizers, soups or sun-dried. They are larger than cherry tomatoes and have an oblong shape.
Beefsteak tomatoes are the heaviest weighing even more than 200g. These tomatoes have a lean texture which is perfect for grilling, packing and they are often used on sandwiches.
Cordon or indeterminate tomatoes
Indeterminate plants develop extensively and soaring above until you finally stop them. Their fruit is carried on the shoots coming off the chief stalk. Harvest extends over a sustained duration. Conveniently plant them in raised beds, grow bags, or transplant them into the garden when the soil temperature moves at least 55°F. Support them with tall stakes. This variety is the most popular and is developed as single stemmed plants with eliminated side shoots.
Bush or determinate tomatoes
Determinate plants develop reasonably compact bushes with smaller main stalks and they are just perfect for smaller spaces. This variety stops growing earlier than cordon. They are also called as a dwarf variety which is advisable in hanging baskets. They do not expect pruning.
Their fruit ripens all at the same time. They are best raised in huge pots, containers, raised beds, and grow bags. Use containers that can hold five gallons or more. The pots require sufficient drainage holes. Apply fresh potting soil that flows thoroughly. Stake them in advance. Container plants expect constant watering. Never prune side shoots, because these are your tomato’s fruiting shoots.
Semi indeterminate varieties are like bush tomatoes. They are grown as determinate but they just bear smaller plants.
How to set up your greenhouse for your tomatoes
The first step involves checking the temperature, selecting the right tomato variety, choosing a medium to grow the crop, and installing the recommended irrigation system.
- Tomato plants provide better yields if day temperatures range from 70°F to 80°F and night temperatures from 60°F to 65°F respectively. This accurate warmth inside helps you grow tomatoes in a greenhouse with higher expected yields.
- When selecting a variety, choose seeds that are marked as ‘greenhouse varieties’ since these are tolerant of the conditions inside a greenhouse. Choose the letters VFNT and A after the name indicate that the type is resistant to diseases. If you are doubtful about what seeds to buy, then it may be wise to talk to local growers. Their wealth of information will easily lead you in the right direction.
- Generally, tomatoes thrive in a well-draining medium such as a soilless medium, Rockwool slabs or perlite bags, vermiculite and sphagnum peat moss mixed in the ratio 1:1.
- It is recommended to use a drip irrigation system because it provides a steady supply of water directly to the root system and you can also use it to automate the fertilizer application.
- Keep moisture under 90% to prevent leaf mold. Regular ventilation brings fresh and dry air particularly when it is cold.
How to grow tomatoes in a greenhouse
- You may use a soilless tray and seed nutrient solution. RSI Hydroponic Floating Seeding Trays will give you a high success rate of transplanting your tomatoes.
- Get the tray ready by making it moist using water or nutrient solution. Water is appropriate for moisturizing soil while the nutrient solution is meant for a soilless tray.
- Plain water is advisable until the mixture is quite wet enough to squeeze into a mass, with just a few drops when compressed.
- Ensure you expose the trays to ample lighting. These grow lights will provide your seedlings all the light they require to thrive even in winter.
- Dig a quarter of an inch hole inside every cell of your seeding tray. Shoot a single seed inside each hole. Coat carefully with your potting mix. Plant around 10 to 15% extra seeds that you intend on growing, so you can ditch the least vigorous seedlings.
- The seeds normally sprout in one or two weeks.
- Transplant them into small pots and then again into bigger pots when they attain a height between four to six inches. These raised beds can give your tomatoes the sufficient space they need.
- Regularly apply nitrogen and potassium-rich fertilizer.
- Remove offshoots weekly. Do not leave a piece behind that may die after.
- It is best to use trellises or stakes for them to climb straight and spread out.
- You may also need to use a mechanical pollinator on the tomato plants to help pollinate the flowers and prune the leaves when the plants begin to fruit. Check out more about the VegiBee Garden Rechargeable Pollinator here!
- Guard them against the freezing temperature and intense winds which may destroy them.
- Remember that even bigger species may bear less fruit if planted in smaller containers. Starting them near each other can reduce air circulation and promote disease.
- Ensure that the calcium and pH levels are appropriate in the greenhouse before this last transplantation.
- If the soil is acidic, you can combine about one teaspoon of hydrated lime per gallon of potting mixture.
You can choose to plant tomatoes in the greenhouse border for them to have a sufficient place to climb, get enough sunlight, and for them to get enough water most of the time. There will be lesser chances of getting diseases but they may not have enough water. So make sure to address this concern when planting in pots and bags.
Recommended Tomato Greenhouse: Arcus
Save your time and energy from moving your tomatoes in and out of the greenhouse just to get sufficient air and sunlight. With the Arcus, you can plant and raise them directly inside your greenhouse. Bees and other beneficial insects can visit and pollinate your plants anytime you want by opening the sidewalls.
Introducing the absolute ventilating greenhouse with no additional ventilation system needed. All you need to do is slide up the walls and feel the cool breeze. Polycarbonate walls offer stability, insulation, and UV-protection. Install it on almost all ground types. Enjoy the summer and feel secure in wintertime. Get more information about the Arcus Greenhouses here!
Pests and disease control
- Remember to regularly ventilate your greenhouse in summer to deter pests and diseases.
- Replace the soil before growing another batch of tomatoes to prevent pests and root diseases.
- Maintain a moist soil but be mindful not to over-water since damp soil may promote damping-off disease and additional mold problems.
- Do not install an overhead irrigation system because the leaves of tomato plants are susceptible to diseases.
- Pruning the falling leaves to allow more sunlight to prevent grey mold fungus.
Those thick bunches of tiny aphids can be on the stems or brand new leaves of your tomatoes. It is not really a big deal if it is just a small number. Don’t be discouraged to mash them using your thumb because extensive infestations can deliberately damage or even destroy your crop. Take off the leaves where aphids are clustered, and throw these cut portions into the garbage bin and not on the soil. If it still persists, use the insecticidal detergent that uses organic materials.
Damping off is caused by some viruses. This disease is a tomato dilemma that concerns fragile, obviously healthful seedlings that quickly form a dark wound at the soil line, and suddenly wilt and rot. Cool, wet soil, overcrowding and overwatering can cause this contamination. Make sure to use clean potting soil, seed trays, and accessories to lessen the rate, prevent packed seedbeds, and control watering thoroughly throughout the first two weeks after germinating.
Fusarium wilt is caused by a soil borne fungus that aims tomatoes, potatoes, peppers, and eggplant. It usually creates no indications until the plants are ripened and green fruit starts to attain its grown size. At that time leaves on the side of your plant becomes yellow, and a sliced stalk will reveal brownish, smeared tissue. Crop rotation helps so the wilt parasites will lose its host and will die eventually in the affected ground where it lives. Cool and soggy situations favor this disease. Never spray water on leaves, particularly in cold weather.
Water your tomatoes properly
For a bountiful crop, make sure to water them regularly. Tomatoes are always craving for water. You can use tap water or rainwater from water butts.
Harvesting your tomatoes
The longer your tomatoes stay on its vine, the fuller and redder they mature. You can harvest anytime depending on how full and red you want them to be. Do not put them on a sunny spot to ripen because they may decompose even before they ripen. The best time of day to pick tomatoes is early in the morning.
How to properly store tomatoes
Tomatoes don’t freeze well so it is better eaten straight after picking. It ripens fast so don’t let it stay in your kitchen for more than a week. If you have too many tomatoes at once, you could preserve them.
If you are ready to start growing purchase your tomato seeds here.
Let us know your experience of planting and growing your own tomatoes. Leave us a comment below!
For those of us who grow tomatoes in a greenhouse and outside in the garden, there is no competition – the greenhouse wins every time!
The patio is fine for growing bush varieties in large pots and hanging baskets or tall varieties up against a wall in grow bags, but to guarantee a successful crop each season, a greenhouse is the best place to grow tomatoes.
If you live in a short season area such as the UK, a greenhouse has the benefit of being able to start sowing earlier in the season.
This will enable you to still be picking tomatoes when plants that were grown outside have long finished.
In a greenhouse, tomato plants are out of the rain, also temperatures won’t drop so low at night.
The combination of wet leaves and cold temperatures for more than a day or two, will have a serious effect on a tomato plant’s health.
This is owing to blight and the many other fungal diseases waiting to strike plants that are both wet and cold.
When a tomato plant growing outside has wet leaves, it is unable to absorb water through its roots, therefore, the nutrients that the water carries, is not taken up by the plant.
It then goes hungry and is more vulnerable to diseases. In contrast, a plant grown in a greenhouse with dry leaves, will be able to absorb nutrients whenever it wishes and will grow at a more consistent rate.
Temperatures fluctuate less widely inside than those outside in the garden, so this will also aid steady growth and encourage pollination and flower set. Getting flowers to set fruit can be a real problem if it gets too cold at night.
A greenhouse also has the benefit of being able to shade tomatoes from direct sunlight.
This may seem rather strange – shielding plants from the sun! However, some tomato varieties, especially those that originate from cooler climates, such as many of the black varieties, prefer diffused sunlight on a hot summer’s day. So setting up a sheet of garden fleece, or using some other means of shading between the hot sun and seedlings, is easy.
The ability to control temperatures in a greenhouse enables optimum plant growth.
We all know that tomato plants like warm conditions, but warm conditions enable plants to feed regularly.
When temperatures are too low, nutrients are unable to be absorbed, so cold plants are also hungry plants – just like wet plants are hungry plants!
Of course, good ventilation is necessary to avoid high humidity and condensation.
Tomato plants need good air circulation and if doors are closed on a greenhouse full of tomato plants, they will soon use up the carbon dioxide in the air and their growth will slow down.
To sum up, the benefits of growing tomatoes in a greenhouse allow us to focus on actually growing the fruit, rather than just hoping that we will get a crop, and that our plants will make it through to the end of the season!
Thinking About Greenhouse Tomatoes?
By Rick Snyder
By Rick Snyder
Where To Find More Information
For more information on greenhouse tomatoes, visit the Greenhouse Tomato FAQ Web site at ext.msstate.edu/anr/
plantsoil/vegfruit/tomato/ghtomato/faq.html. In addition to many frequently asked questions, it has links to entire documents on production and pest management, and a comprehensive list of other Web sites that should provide valuable information.
Attending short courses that are geared specifically toward greenhouse tomato production is another excellent way to learn a lot about this crop. There are state greenhouse vegetable programs each year in Florida, Mississippi, New Jersey, North Carolina and Texas. Also, The Ohio Short Course will have a greenhouse vegetable session in its conference schedule for 2001. It is well worth the expense to travel to a short course in another state to learn as much as possible about production techniques and potential problems.
Rick Snyder is an extension vegetable specialist at the Truck Crops Experiment Station, Mississippi State University, Crystal Springs, Miss. He can be reached via email at
Scientists Discover Why Most Tomatoes Taste Awful—And How To Fix It
Greenhouse tomatoes are a crime against humanity. Ask any foodie — the ideal tomato is grown outdoors in the finest soil; it matures throughout the early and midsummer, just in time for harvest before winter temperatures sweep in and ruin the crop. Out-of-season tomatoes, often grown in large commercial greenhouses, are all but inedible to the sophisticated tomato-lover’s palate.
Until now, the reason why out-of-season greenhouse tomatoes taste awful eluded us. But a new study in the Journal Of Agricultural And Food Chemistry suggests that the lack of ultraviolet light in a greenhouse may be part of the problem. Researchers found that the glass walls of the greenhouse block UV light, which can cause stress in tomato plants that may alter the fruits’ ultimate flavor. And when they artificially introduced ultraviolet rays into the mix, taste testers loved the result.
“Fruits harvested from off-season, greenhouse-grown tomato plants have a poor reputation,” the authors write. “These studies represent the first reported use of…UV radiation throughout the…tomato plant life cycle to positively enhance the sensory and chemical properties of fruits.”
For the study, researchers grew tomatoes under a variety of conditions — in a conventional greenhouse (ugh), outdoors during the summer, and in a greenhouse supplemented with UV light. They then asked volunteers to rate the tomatoes based on color, aroma, sweetness, acidity, aftertaste, and texture. Never before had a tomato’s identity been subject to such scrutiny.
The clear winner? Outdoor tomatoes, of course. Outdoor tomatoes had an “overall approval” rating of 6.61 out of 9, but UV-supplemented tomatoes came in close second at 6.49. And after they crunched the numbers, the researchers found that the difference between those ratings was not statistically significant — in other words, from a numbers standpoint, tasters cannot tell the difference between UV-supplemented greenhouse tomatoes and good ol’ fashioned outdoor tomatoes.
But they still hate conventional greenhouse tomatoes — those grown without UV-supplementation garnered a dismal score of 5.67, which was quite statistically significant. So see, they’re still gross.
The findings suggest that tomato growers who are looking for a year-round solution should consider UV-light supplementation. “Pre-harvest treatments enhanced sensory perception of aroma, acidity, and overall approval,” the authors write. “Suggesting a compelling opportunity to environmentally enhance the flavor of greenhouse-grown tomatoes.” Not that it’d be hard to enhance a 5.67.
Hothouse Tomatoes Pack Summer Flavor in the Springtime
It’s April, and after months of carrots and kale, you’re probably itching for a sliced tomato in your salad or some fresh salsa for your chips. But if you’ve bitten into a supermarket tomato in the winter or spring, you know that they’re generally a bland, watery, and pale imitation of their summer counterparts.
There’s of course a reason: tomatoes don’t naturally grow year-round here, as they need warmth and sunshine to develop. The modern, industrial tomato that you find in most grocery stores is bred for appearance and durability, so it can be picked unripe and shipped long distances to feed America’s tomato addiction, no matter the time of year (or how lackluster the flavor).
Fortunately for us, Peach Farm and Elston Family Farm grow tomatoes in hothouses (heated greenhouses) to extend the season, and their vine-ripened tomatoes hit the farmers market this month, providing a sweet taste of the warm season ahead.
Indoor Tomatoes 101
California leads the country in summer tomato production, but most tomatoes you find in the winter and early spring are grown in Mexico or Florida. In the U.S., hothouse production is on the rise, giving hope for a more flavorful off-season tomato.
Some greenhouse tomatoes are produced hydroponically, getting their nutrients from a water solution rather than soil, but both Peach Farm and Elston Family Farm use a soil potting mix. To avoid pesticides, they release “beneficial insects” in the greenhouses to manage pests naturally, such as ladybugs to control aphids.
There are tradeoffs in hothouse farming; growing crops indoors in containers requires more labor and resources. To create the perfect environment, growers must maintain a balance of temperature, humidity, nutrition, and water. Hothouses are heated in the winter and cooled in the summer, making energy costs high. But for certain growers and tomato lovers, a ripe, locally grown spring tomato is well worth it.
Carrying On a Greenhouse Legacy
Ferry Plaza Farmers Market customers know Ed George of Peach Farm for his heirloom tomatoes, peppers, squash, and figs in the summer months. A third-generation farmer, Ed embarked on his own farming path in Yolo County in the 1970s.
This year, he’s at the farmers market several months ahead of his usual schedule. Last fall, he purchased 11 greenhouses from Nick and Jane Atallah of Madison Growers, another beloved Ferry Plaza original, expanding Peach Farm’s offerings and growing season.
Nick, an agriculture and water expert who taught at American University of Beirut in Lebanon and later worked with USDA, started Madison Growers with Jane in the 1980s when he retired. Over the years, they developed a loyal following for their flavorful, uniformly sized, and blemish-free hothouse tomatoes as well as Mediterranean and Japanese cucumbers.
Nick passed away in January from complications from myasthenia gravis, an autoimmune disorder, but he and Jane transitioned the business to Ed last year.
“As Nick’s health was declining, we contemplated selling the farm because we couldn’t keep it running,” says Jane. One day Ed approached them at the farmers market, having heard they were looking to sell. “He was interested and gave us a proper deal. He was already farming in that area, so it was a perfect fit.”
Extending the Season
Ed has started adding a few new varieties to the greenhouses, but for the most part, has kept the Atallahs’ operation as is, down to using Nick’s special proprietary potting mix. “Nick was a smart man and had everything dialed in,” he says. “For me to step in and take over what they worked for 28 years to accomplish means a lot.”
All of Madison Growers’ workers have continued on with Ed, including their greenhouse manager, Pepe, who has been with the farm for 18 years. As Ed learns the peculiarities of hothouse production, he is grateful for the steady stewardship of the experienced staff.
“I was out there yesterday, and everything is going on as Nick had established,” says Jane. “So the success is that what Nick developed continues. That’s his legacy.”
The transition has allowed Peach Farm to extend its market season, so that Ed can now supply customers with summer produce roughly nine months out of the year. “It makes our farm more complete,” he says. “We get in the markets a couple months earlier, then shift into summer produce, then pick up greenhouses again in the fall and keep the cucumbers going until Christmas.”
In a record-breaking year of rain, in which many farmers have had difficulties planting crops in muddy fields, having greenhouses offers some control and predictability. “It’s been raining, and you go inside these greenhouses and you still have ripe tomatoes. It’s like a different world in there,” says Ed.
Old Habits Are Hard to Quit
At Elston Family Farm, just north of Paso Robles, Dennis and Gaylo Elston and their daughter, Mary, have grown hothouse tomatoes and cucumbers for 20 years. The Elstons’ market season generally runs April through July, ending when field-grown tomatoes start hitting the market stands.
Gaylo can attest to the labor and delicacy it takes to nurture these crops to ripeness for peak flavor. “They’re like babies,” she says. “They have to be a certain temperature all the time—not too hot, not too cold.” The Elstons use grow lights and propane heating for their fledgling plants in the winter months, while in the summer their greenhouses are cooled with fans and evaporative cooling pads.
Neither Dennis nor Mary likes tomatoes, which makes Gaylo the resident taste tester. “Our tomatoes are sweet. I think it’s because we grow in dirt and not in water,” she says. Dennis prefers the cucumbers: “I’ll eat them for breakfast when I’m out there picking them.”
In this family operation, Mary manages much of the workload in addition to her full-time job, and Gaylo steps in as needed. Dennis, now 76, doesn’t foresee retiring until he needs to. “I’ve got a fold-back easy chair and a TV, but I’m afraid that’s where I’ll live and die if quit the tomatoes,” he says.
He recently replaced the plastic covers on the greenhouses, a major investment. “When you put on new plastic, then you’re in for another four or five years,” says Dennis. “It’s hard to quit. I’ve been at it a long time.”
Find Peach Farm on Saturdays and Thursdays, and Elston Family Farm on Saturdays at the Ferry Plaza Farmers Market.
Farm photos courtesy of Peach Farm.
How to Grow Your Own Tomatoes, Part 1: Starting Seeds Indoors
If you peruse a seed catalog, especially one geared toward heirloom vegetables, you’ll quickly realize that the selection of tomato transplants in nurseries pales in comparison to the variety of seed that are available. Names like ‘Aunt Ruby’s German Green Tomato’ and ‘Missouri Pink Love Apple Tomato’ have been ascribed to varieties whose flavor and appearance are as eclectic and unexpected as their names imply. Growing from seed gives you the chance to experiment with some of these more unusual varieties.
Growing tomatoes from seed isn’t hard, but there are a few things to be aware of. As with all things agrarian, timing, genetics and environment have to be in alignment to reap the rewards of your efforts.
Time and Place
Tomato seeds are almost always started indoors – whether in a greenhouse or a sunny window ledge – and then transplanted to beds once they have at least a few leaves and an established root system. Starting seeds indoors is optional with many vegetables, but tomato seeds need a constant soil temperature of at least 60 degrees, and preferably 80 degrees, to germinate. In temperate climates, it may be midsummer before the soil gets that warm, and by then it’s too late for tomatoes to grow and mature before the end of the growing season.
Tomato seeds are typically started “six to eight weeks before the average date of last frost,” as the seed packets so ubiquitously state. Tomatoes originate deep in the tropics; temperatures below 32 degrees Fahrenheit are their death knell. And because they take three months or so to produce ripe fruit, most gardeners want to get the process started early.
So how do you know when your average date of last frost is? In the past, you might have consulted the Old Farmer’s Almanac. Today there are many websites that can tell you, including Modern Farmer’s own quick and handy frost chart. To give you an idea of the range: in Savannah, Georgia, it’s March 1; in Bozeman, Montana, it’s May 26. Find yours, subtract six to eight weeks and plant your tomato seeds.
‘Soilless’ potting mix (available at any garden center) is the medium of choice for sowing tomato seeds, though you can opt for the more expensive ‘seeding mix’ if you want. As for the container, cell packs (the tiny plastic pots grouped together in packs often used for flower and veggie seedlings) are OK for starting tomato seeds, but a better idea is to use a small pot at least 3 or 4 inches tall and wide so the seedlings can grow to a healthy size without their roots being constricted.
The three most important steps are:
- Fill the pots with potting mix to within a 1/2-inch of the top and place a pair of seeds on top of the soil in each one near the center of the pot (having two is good insurance in case one doesn’t sprout. Pinch off the smaller, weaker of the two if they both sprout).
- Cover them with a ¼-inch layer of soil mix and the compress the soil with your fingers. Good seed-to-soil contact is important for germination.
- Sprinkle water on the seeds whenever the top of the soil mix appears dry. Don’t keep the soil soggy, however – the seeds may rot.
The seeds will need a sunny window with at least 4 hours of direct sun each day, but preferably more. Also: the warmer it is, the faster tomato seeds will germinate. Maintaining room temperature above 60ºF will get the job done, but there are also seedling heat mats, heat lamps and many other tricks that farmers and gardeners have concocted to speed up the process. A simple approach is to cover the pots tightly with plastic and take advantage of the greenhouse effect to warm up the soil when the sun is out and hold on to the heat at night.
There is an important caveat about tomato seedlings and mini-greenhouses: If you’re covering your seeds to keep them warm, you must remove the cover as soon as they start to germinate. Otherwise, they may succumb to damping off disease, a fungal infection that proliferates in still, moist air. This appears as brown and grey spots on the leaves followed soon after by the death of the seedling). Damping off is a big challenge with tomato seedlings in general, so try to provide good air circulation during their infancy period indoors. A tiny fan or heat vent nearby is helpful, as is an open window from time to time (but only when outdoor temps get up to room temp).
There are thousands of tomato varieties, but they all fall into a few broad categories. A single plant may produce scores of tomatoes over the course of the season, so you may want to strategize and plant one or two from each of the main categories.
Cherry tomatoes, such as Sun Gold, Napa Grape and Pear Drops, have the quintessential sweet-tart tomato flavor and are great for salads and snacking on whole. Because the fruit is small, these are the first to mature.
Sauce tomatoes, such as Roma, Amish Paste and Big Mama, have a richer flavor and much lower water content than other varieties. They’re the best ones for spaghetti sauce.
Beefsteak tomatoes, such as Mortgage Lifter, Cherokee Purple and Brandywine, have the biggest fruit and the greatest range of flavor and form. They are commonly sliced for sandwiches or making caprese salad, though the best varieties can be eaten like an apple.
There are also many all-purpose tomato varieties that have traits from each category. Most of the round, tennis ball size tomatoes at the supermarket would be classified as all-purpose. These are usually modern hybrids that rarely match the complex flavor – and diverse appearances – of heirloom tomatoes.
Finally, there is one often overlooked tomato trait that is quite important to be aware of. Somewhere on the seed packet in fine print you may find the words “determinate” or “indeterminate.” The former means the plant will grow to a certain, genetically determined size and then stop (the packet should indicate the size). The latter will grow indefinitely, as long as freezing temperatures or other acts of nature (or humans) don’t stop it.
Few people realize that in their tropical homeland, tomatoes are actually perennial vegetables, meaning they grow year after year, not for just one season. In the tropics (or here, in a greenhouse) indeterminate tomatoes eventually become vines more than 20 feet long. The practical ramifications for North American growers are that indeterminate tomatoes need much more space – they can easily grow 6 or 8 feet in a six-month growing season before succumbing to frost. If you want a compact tomato plant that fits inside a standard 3- or 4-foot tomato cage, go with a determinate variety. You will get more tomatoes overall with an indeterminate variety, but determinate varieties typically yield more fruit per square foot.
Planting tomatoes according to the local date of last frost is a no-brainer. But if you want to get metaphysical about it, consider the position of the moon and stars. Biodynamic growers are highly attuned to cosmic influences in agriculture and plant according to a yearly calendar based on celestial events.
Farmer’s almanacs have traditionally been based on the same phenomenon. For example, the current Farmer’s Almanac says that March 24 and 25, 2015, are terrible times for planting any seeds, but recommends April 3 for tomato planting in particular.
Join us again in early May for part two of the series, where we’ll lay out the finer points of “hardening off” the seedlings, preparing the soil and providing your sensitive seedlings with just the right juju to grow lavishly and fruitfully through the summer.
Growing Tomatoes in a Greenhouse
Those who are new to greenhouse gardening often think that glasshouses are best suited to growing flowers, herbs, and perhaps cool season crops like leafy green vegetables. The common belief among novices is that “picky” summer vegetables like tomatoes and peppers can be started in a greenhouse in late winter or early spring, but must be moved outdoors once the weather warms up.
That couldn’t be further from the truth. While it may be easier for a newbie to tend a tomato crop planted outdoors, growing tomatoes in a greenhouse isn’t difficult once you get the hang of it – and nothing beats having a year-round supply of delicious, home-grown tomatoes. Growing Tomatoes outside can be quite challenging given the UK’s unreliable climate and weather conditions. Growing tomatoes under glass will always yield far more fruitful crops, year in, year out.
Before starting, it’s important to ensure that you have the proper environment for growing tomatoes in your greenhouse. Unless it’s already summer and you’re planting for a fall crop, you will probably need to supplement the natural light inside your glasshouse with grow lights timed to operate 12-16 hours per day (high-pressure sodium lights are the best choice because they facilitate the growth of tomato flowers and fruit), and you may need to add heaters and timers to maintain proper indoor temperature. If possible, nighttime temperatures between 15 and 18 degrees and daytime temps between 22 and 28 degrees are optimal; heat mats placed under the plants can help as well. Finally, good air circulation is important to maintain constant humidity and prevent the spread of airborne plant disease.
Ready to grow? Here’s your guide to growing tomatoes in a greenhouse.
When to Plant Tomatoes in Your Greenhouse
When to plant? Hey, you’ve got a greenhouse – you can plant anytime you want! Seriously, though, most gardeners want to have an outdoor tomato crop during the summer, so we’ll start there.
The first step is finding the “last frost date” for your immediate area, which will tell you approximately when the danger of winter frost has passed. With that information, you can count backward to the proper date to start your tomato seeds. There are a number of online resources which allow you to enter your region or town and find out the proper last frost date to use. You should start your seeds six weeks before that date, and plant the seedlings outdoors between a week and ten days after the last frost date; that’s to avoid the danger of a very late surprise frost, and also because tender plants appreciate it when you give the ground an extra week or so to warm up. In the UK, the normal period for sowing seeds is between the start of March and the end of April. You can check out our greenhouse growing guide for advice on the timings for planting and harvesting of all manner of plants and vegetables.
Of course, the real advantage of having a properly-heated glasshouse with adequate lighting is that you don’t have to be a slave to the seasons and can sow your seeds at any time. That doesn’t mean you can just throw some seeds into some soil and be feasting on juicy red tomatoes on New Year’s Day, however. All tomato plants require plenty of attention, but those grown during the cold seasons need extra care – and that begins with choosing the right plants.“Determinate” varieties, often called bush tomatoes, are hardier and better suited to late summer, fall and winter planting because their shapes provide better protection for the fruit and take up less space, making them the best choice for most home greenhouses where space can be at a premium and temperatures can vary. Determinate tomatoes produce their crops all at once rather than fruiting throughout their growing season (like the indeterminate varieties which prosper outdoors during the summer). Staggered planting dates throughout the cold weather months can ensure a continuous supply of greenhouse tomatoes.Indeterminate varieties can be grown in a glasshouse as well, but will grow much higher and require strong support for the vines; many feel cherry or plum tomatoes are the best indeterminate for indoor growing. In general, indeterminate tomato plants will produce a bigger crop, but determinate varieties will give you more fruit per square metre.We’ll get into the specifics of planting seeds and tending plants shortly, but be aware that growing “off-season” tomatoes in a greenhouse during winter’s shorter days (with less natural sunlight) and in colder weather demands greater attention to maintaining proper temperatures and humidity, and positioning plants so they receive as much sunlight as possible (supplemented by grow lights as needed).
Growing Tomatoes from Seeds
There’s certainly less effort needed to start your indoor tomato garden with plants from the garden centre, but it’s more rewarding to grow tomatoes from seeds and watch the first seedlings emerge. If you’ve never done it, it’s worth the extra time just to experience the thrill of seeing the small plants grow and thrive. You’ll also have a much greater choice of varieties when growing from seeds.
One of the most important decisions you’ll have to make comes well before you see fruit, shoots or even the first sprouts – it’s choosing the tomatoes you plan to grow. We’ve already mentioned the difference between determinate and indeterminate varieties; the amount of room you have in your greenhouse and the type of fruit you prefer should both be considered when making this decision. Most seed suppliers and online sites clearly label the best choices for greenhouse growing; a few commonly suggested varieties are Roma VF, Tumbling Tom and Red Alert for bush plants, and Alicante, Gardener’s Delight and Shirley for indeterminate plants which will be cordoned (more about that later in this article).
Now that you’ve selected seeds, it’s time to sow them. The process is the same whether you plan to keep them indoors in pots, move them to grow bags, or transplant them into the ground inside your greenhouse or outdoors. You’ll initially sow the seeds in pots, so let’s start there.
Growing Tomatoes in Pots
Some gardeners start their seeds the way that commercial operations do, in the small cell packs that are sold to consumers. There’s nothing wrong with that, but you’re better off using small 7.5-10 cm tall pots, wide enough to let the seedlings spread their roots. Fill the pots almost completely (leave about 1 cm of space at the top) with soilless potting mix, seeding or multipurpose compost, and place a few seeds on top near the middle of the pot. Most of the seeds will germinate, so don’t put too many in each pot – three to five seeds should do it. Cover them with a thin layer of soil mix or compost and press down gently so the seeds are completely in contact with the soil. Don’t forget to label the pots with their variety and starting date.
Now place the pots in an area of your greenhouse which receives at least four hours of direct sunlight per day. The more sunlight and the warmer the environment, the faster the seeds will germinate; the grow mats and grow lights we’ve mentioned will be a big help. You can even cover the pots with plastic to keep the heat in. If you take the plastic shortcut, though, be sure to remove the plastic as soon as you see the first sprouts. Otherwise, the chances are good that your plants will suffer from a lack of air circulation, contract the fungal infection known as “damping off” disease, and die.
Don’t overwater your seeds because they will rot in soggy soil. When the topsoil becomes dry, just sprinkle enough water into the pots to moisten it. You should see seedlings within about two weeks, and in six to eight weeks they should be large enough to be transplanted into their own, larger pots. During that growing period, be sure to provide good air circulation for the seedlings with an open window or a small fan, and if the greenhouse is cold at night, consider using horticultural fleece to warm the small plants.
It’s time to transplant the seedlings when they’re 2-3 cm tall and have developed a few leaves. Place each into a separate pot, handling them by their leaves and making sure the roots go as deeply into the compost or potting mix as possible. Once a plant has grown to about 20 cm it is ready to be transplanted again, into its “final” pot, a grow bag, or the ground. If the final destination is outdoors, don’t move plants them until it’s warm enough – usually mid-May or later in the UK – and be sure to harden them off first.
For tomato plants which will remain in pots for the entire season, don’t skimp on the size. If a plant outgrows its “final” pot, it’s a major project to transplant it again. Smaller varieties like bush plants or cherry tomato vines should go into a six litre (or bigger) pot, while indeterminate varieties will need one that’s at least ten litres. There should be many small holes in those pots (if you don’t use specially-designed containers like Airpots, you can drill your own) so the roots can breathe. Some pots are more like decorative garden ornaments, shaped like pagodas or drinking troughs. All are ideal providing the size is such that the plants can root down and spread adequately.
You will of course position your tomatoes where they have room to grow and receive as much sunlight as possible, but also be certain that you place the pots where you can provide support for the plants. Even bush tomatoes can benefit from supports like cages, but vining varieties will require cages, trellises or stakes.
Growing Tomatoes in Grow Bags
Grow bags became quite popular in the 1970s as a way to cultivate tomatoes along the inside borders of a greenhouse without “using up” the soil in the ground or exposing plants to diseases or pests which might be present in the soil. They fell out of favour for a while, but are once again popular – and a terrific way to grow tomatoes in a glasshouse (or outdoors, to make the most of a short growing season).
Ready-made grow bags the easiest to use, and also contain compost designed to work without the drainage normally provided by the holes at the bottom and sides of pots. If you’re planting directly into bags of compost or making your own bags, though, you’re best off puncturing the bottom of the bag in a few spots because your plants will most likely need the drainage help. There are also grow bags made of porous material, which provide the best drainage and aeration possible for your tomato plants.To get the bag ready, use your hands to break up all clumps of compost which may have formed inside, then open the pre-cut slots at the top (or cut your own, if necessary). Soak the pot containing your small tomato plant in water for an hour to prevent root damage and then use a trowel to create space for your plant and its root ball. The hole should be deep enough so the top of the root ball sits completely inside the bag and can be covered with a thin layer of compost. Gently firm the plant and the topsoil, and water well.Remember, the plants will get much larger and their roots will spread inside the bag. A 60-litre grow bag shouldn’t be home to more than two plants, and a 75-litre bag should hold three at most. A grow bag support frame can be a worthwhile investment, as it slips underneath the bag and holds canes or poles used to support the plants as they grow.
Some Great Greenhouses to Grow Tomatoes in.
There are a number of different compost products on the market. Seeding compost is light on nutrients while potting compost has the nutrients your plants will need as they grow, and multipurpose compost can be used for both seeds and plants. The ideal approach is using the “proper” compost for each stage of your plants’ development, but that can get expensive. A cheaper approach is to purchase grow bags – even if you don’t plan to use the bags – and use the compost that’s inside the bags. It’s the same quality of compost that most commercial growers use, and if they do fine with it, you can as well. If you have your own compost pile, don’t hesitate to use it; many experts swear by homemade compost for their tomato crops.
The term “cordon” is often used interchangeably with the term “indeterminate,” but in reality, cordon refers to the stem of an indeterminate tomato plant when it grows without extra branches. How does a plant grow without branches, you ask? That requires some actual gardening. First, though, a very short biology lesson.
The important structural parts of a cordon tomato plant are the roots, the main stem (which grows from the roots), and the leaf stems (also called “trusses”) which grow out from the main stem. The leaf stems are where the flowers grow and the fruit develops. As indeterminate varieties grow, they send out many small side shoots (sometimes called “suckers”) above or below the leaf stems. Those shoots, if left alone, will grow into new “main” stems or create even more side shoots, using up much of the nutrients the plant needs to create fruit.The best crop of tomatoes, therefore, is produced when the plants are pruned (or cordoned) to ensure that they only have one main stem. That is done by pinching off those small side shoots regularly; checking each plant once a week will let you catch the side shoots early enough that they’ll snap off easily in your thumb and forefinger when you bend them. As long as you don’t accidentally remove or damage the leaf stems above the shoots, you’ll end up having a single tall vine with productive leaf stems growing lots of tomatoes.
A cordon tomato plant probably will never grow tall enough to let Jack climb up to find the Giant’s gold, but it will keep on growing and growing – and diverting nutrients to the new growth – unless you stop it. That’s easy to do by a process known as stopping tomatoes (sometimes called topping tomatoes).
Once a plant has grown four to six leaf stems (the decision depends on how tall your greenhouse is and how well the plant is flourishing) it’s time to stop its upward growth by cutting the main stem at a point two leaves above the top leaf stem. From that point on, all of the plant’s energy will be used to grow those beautiful red tomatoes on your existing trusses.
Determinate varieties do not need to have side shoots removed or to be stopped.
Feeding Your Tomatoes
There’s nothing complicated about feeding your greenhouse tomato plants. Simply use a nitrogen-rich liquid fertiliser every one or two weeks (read the label on the container to determine the optimal feeding schedule) while the plants are first growing, and then switch to a high-potash, high-potassium “tomato plant” fertiliser after the first tomatoes have started to set.
Two other quick feeding facts: first, if you have a sick plant it should not be fed; starve the plant until it starts to recover. Second, liquid fertiliser leads to an accumulation of salts in the compost. Skip a feeding twice during the plant’s life cycle and give lots of extra water instead, to wash out some of the salts.
Watering Your Tomatoes
A general benchmark is that a greenhouse tomato plant needs a little over one litre of water per day, more in hot and sunny conditions, less in cool and cloudy conditions. Plants appreciate daily, light watering much more than being drenched every once in a while. The latter will lead to cracking or splitting in the tomatoes’ skins.
The best way to know if your tomato plants need water is to examine the soil and the plants. The soil from the top to a depth of 5 cm should be moist but not soggy and the leaves should not be wilting. Dry soil and wilted or dark green leaves are a clear indication that the plants aren’t getting enough water. On the other hand, soggy soil and light (almost yellow) leaves are signs that you need to cut back on your watering.
Tomato Diseases and Pests
When you grow tomatoes in a greenhouse, they’re less susceptible to blight than ones growing outdoors. However, there are two pests which are quite common to glasshouses and can do great damage to your tomatoes.
- Red Spider Mite: You can’t see these mites (which love the protected environment of a greenhouse) with the naked eye, but you’ll know there’s a problem if you see mottling, bronzing or speckling on the top of your plants’ leaves. Immediately turn down the heat and continually mist the underside of the leaves (where the mites nest) with water; then get a predatory mite called phytoselius persimilis, which will eat the red spider mites, at your local garden centre. Avoid pesticides, because they won’t kill the red spider mites but will kill the “good guys” instead.
- Whitefly: Whiteflies show up in the spring and start as tiny (1.5 mm), scaly crawlers before becoming small white moths as adults. It’s best to be proactive because whiteflies are quite common in glasshouses. There’s a two-step process: in early April introduce the parasitic wasp known as encarsia formosa, which will eat the nymphs, into the greenhouse. Then later in the month, hang fly-catching sheets near your plants to catch the adults. Most whiteflies are resistant to pesticides; the sprays that do still work can also be absorbed by your tomatoes.Other issues which affect outdoor tomatoes can be a problem in greenhouses as well. Growing marigolds near your tomatoes will help attract hoverflies if you have an issue with aphids, but many chemical sprays will also do the job. Mosaic virus is also a major issue in the UK, and is distinguished by leaves which become misshapen and a mottled yellow in color. Remove the leaves from plants and from the greenhouse immediately, be sure not to touch any other plants until you’ve washed thoroughly, and give the affected plants plenty of food and water – they should recover much of their strength.
How to grow tomatoes
Speedily grown under glass, placed in cold storage and ripened with gases… it’s hardly surprising that commercially grown tomatoes often taste bland. They’re a world away from home-grown tomatoes, which are juicy and have tangy flavours that develop gently over summer, as they ripen.
More expert advice on growing tomatoes:
- 10 of the best tomatoes to grow
- Blight-resistant tomato varieties
- Video: Planting tomatoes in a growing bag
- Tomato types explained
- How to avoid tomato blight
- How to grow tomato plants from cuttings
- How to grow the tastiest tomatoes
- How to boost tomatoes with a comfrey feed
Follow the expert advice in this guide to growing your own delicious crop of tomatoes.
Keep tomatoes well watered because irregular watering causes fruit to split or develop hard black patches. Watering pots of freshly sown tomato seeds
Growing tomatoes from seed
There are many different types of tomato, including cherry, plum and beefsteak, each with its own distinctive shaped fruit, flavour and culinary use. They grow in one of two ways – either as a bush, or trained as a cordon, which is a tall single stem.
Tomatoes are available as young plants, but if you’d like to try some of the more unusual varieties it’s worth growing them from seed.
Start sowing in late January. Sow seeds in 7.5cm pots of moist compost, top with a thin layer of vermiculite, then water and cover with cling film. Stand on a warm, bright windowsill or in a propagator.
When your seeds have germinated, remove the cling film (or take them out of the propagator) and keep the compost damp. Transplant seedlings when they reach about 2-3cm tall into 5cm pots filled with moist multi-purpose compost. Return them to the windowsill. Keep potting on as necessary. Support stems by tying them to a pea stick with soft string.
Planting tomatoes outside
Move your tomatoes outside after the last frost in May. Choose a sunny, sheltered spot, where you can plant them into a border (into soil that has had plenty of well-rotted garden compost added), or into 30cm pots, or put two or three plants in a growing bag. If growing tomatoes in a greenhouse, try growing alongside basil, which enjoys the same conditions.
Watch Alan Titchmarsh’s video guide to planting tomatoes in a growing bag:
Looking after cordon and bush tomatoes
Tall-growing cordon tomatoes will require pinching out (removing side shoots) and staking (tying plants to canes with soft string). When the first tiny fruits begin to appear, strip away the leaves underneath to allow light and air to reach them better. When there are four trusses (clusters) of flowers, pinch out the plant’s growing tip.
Watch Alan Tichmarsh’s No Fuss video guide to caring for cordon tomatoes:
Once flowers appear, feed your plants weekly with liquid tomato food, such as Tomorite. Keep tomatoes well watered because irregular watering causes fruit to split or develop hard black patches, known as blossom-end rot. This is caused by a lack of calcium, which is found in water.
With bush tomatoes, which have a sprawling habit, you can pretty much leave them to get on with it. If the fruits are hidden under the leaves, thin out the foliage a little to let the sun through to ripen them. Support heavy trusses on top of upturned flowerpots to prevent their stems snapping.
Ripening tomatoes on the vine
Leave tomatoes on the plants so they can ripen naturally, which greatly improves the flavour. Towards the end of the season, prune off the older leaves to let in more light and prevent grey mould fungus taking hold. If the weather turns cold, pick the trusses to ripen indoors.
Harvesting cherry tomatoes
Tomatoes are best eaten straight from the vine, when they’re still warm from the sun. They don’t freeze well, but you can store them for a week or so. Avoid storing your tomatoes in the fridge where possible, as this will give them a mealy texture.
Preparing and cooking tomatoes
Enjoy tomatoes in salads and sandwiches. Most types are also suitable for cooking, but plum varieties are especially so. If you’re lucky enough to have a glut of tomatoes, try experimenting with your own pasta sauces.
Tomatoes: problem solving
Whitefly can be a problem in greenhouses, and tomato blight can affect plants grown outside, especially in warm, wet summers. Prevent blight by spraying plants with a suitable fungicide. Blossom end rot is caused by a lack of calcium, and splitting fruits can be a result of erratic watering.
Growing tomatoes in a greenhouse
Growing tomatoes in a greenhouse is very similar to growing them outside, except you get a longer growing season. You’ll need to shade your plants from excessive heat, which could cause tough skins, blotchy ripening and, if you forget to water regularly, blossom-end rot. So fit some blinds, use shade paint, or hang woven shading fabric.
Yellow and red tomato varieties
Great tomato varieties to grow
- ‘Astro Ibrido’ – produces vast quantities of small to medium plum tomatoes with outstanding flavour
- ‘Gardeners’ Delight’ – a bush or cordon cherry tomato, with heavy crops of richly flavoured fruits
- ‘Garden Pearl’ – this compact cherry type is ideal for growing in a large pot
- ‘Ildi’ – deliciously sweet, yellow, pear-shaped cherry tomatoes in large trusses of up to 80 fruits
- ‘Juliet’ – a cordon cherry plum, with fewer seeds than most. It cooks well
- ‘Reduna’ – this cordon type has a delicious, classic flavour and is easy to slice
- ‘Sparta’ – a cordon variety with lots of well-shaped and well-flavoured fruits
Growing Tomatoes Anytime in the Greenhouse
Most gardeners will tell you that few things can beat the outstanding, fresh taste of home-grown tomatoes in the summer. Luckily, with a greenhouse you are not limited to the summer months; you can grow delicious tomatoes whenever you want. Tomatoes can be picky plants, but with a little bit of practice anyone should be able to produce their own supply of these mouth-watering delights year-round.
In order to grow the best tomatoes possible, it is important that you give your plants a healthy start. Begin by purchasing seeds developed especially for greenhouse use (readily available in seed catalogs,) which will help you to avoid some common greenhouse problems. Start the seeds in warm conditions, preferably under grow lights and on heat mats, and allow them to develop for a couple weeks before transplanting. Eventually, you’ll want the plants to be in very large containers (at least ten gallons in size) so that they will have adequate room to grow. Be sure that any containers you use have been sanitized with a mild bleach solution to prevent the spread of disease. Also, use fresh soil instead of last year’s, which could possibly pass diseases to your plants. One common problem with greenhouse tomatoes is Blossom End-Rot, a condition that is caused by a calcium deficiency. To compensate for this, be sure to add an additional calcium source to your soil such as bone meal.
Choosing a Location
Tomatoes should only be placed in a greenhouse that is already healthy. If you notice any pre-existing problems with disease or pests, treat these problems before exposing your tomato plants to them. Tomatoes are prone to bugs such as white fly, which can ultimately lead to their detriment. You can minimize these problems by simultaneously planting herbs such as basil and lavender in the greenhouse that will help to deter these pests. Be sure that your tomato plants are placed in a sunny spot that will be near a heat source during cold weather.
Often times the reason that tomatoes will not grow during the winter is that they do not have enough natural light. Because of this, supplemental lighting is almost always required throughout winter months. High-pressure sodium lights should be used for tomatoes because they encourage flowering and fruiting. For best results with tomatoes, lights should be used up to 16-18 hours per day. Make sure to use a light that is the proper wattage for the area you wish to use it in.
If the proper temperature is not maintained within the greenhouse, the tomatoes will fail to produce. You should plan on keeping the greenhouse above 60°F, but below 90°F. In most areas, this will require some heating during cold weather. It is important to get a heater that puts out the proper amount of BTUs for your greenhouse so that the temperature will stay in the proper range. You can use our online heater calculator to find a heater that will suit your needs.
Solexx Greenhouses – perfect diffused light for growing tomatoes
Greenhouse Heaters – An assortment of heaters for the greenhouse
Grow Lights – grow light options to extend to daylight in the greenhouse
Smart Pots – A breathable fabric pot lets you grow big roots in a small pot without getting “potbound” roots
Emilys Garden – Our favorite hydroponic system for growing cherry tomatoes (pictured right)
Trial Criteria for Johnny’s GREENHOUSE VARIETIES
Tomatoes are among the most popular crops for high tunnel and greenhouse production for many reasons: For one, they will produce earlier and later in the season than field crops. Second, quality is generally much better than field-grown because they are protected from weather-related damage (such as splitting, or diluted flavor from heavy rain), which results in higher marketable yields. Additionally, protected culture provides some protection from diseases caused by wet foliage, such as early and late blight. Most importantly, tomatoes are a high-value crop in many markets, and they can produce a steady crop over a long period. A single planting can thus provide a high return on investment with a little regular maintenance.
That said, the high-temperature, high-humidity greenhouse environment is conducive to a different set of diseases, including leaf mold, powdery mildew, fusarium crown and root rot, corky root rot, and botrytis. These fungal diseases are able to spread very rapidly in the close quarters of indoor tomatoes. Soilborne pathogens can build up large populations if tomatoes are grown regularly in the same hoophouse ground; often the high value of tomatoes entices producers to grow them more frequently than they should, without rotating to less valuable crops to break disease cycles. Additionally, symptoms of the tobamoviruses (tobacco mosaic virus and tomato mosaic virus, or TMV and ToMV, respectively) are exacerbated by the restricted light transmission found in greenhouses and high tunnels.
In evaluating dozens of tomato varieties each year for greenhouse culture, Johnny’s looks first for four principal sets of qualities:
- Exceptional vigor and higher yield over a longer season at hotter temperatures than those in the field.
- Resistance to the diseases mentioned above, which are less commonly seen in field production.
- More compact, “polite” plant habits, which reduce the need for pruning and allow better airflow amongst the plants.
- The best flavor and texture possible.
HEATED Greenhouse Production
Go-To Varieties. We carry two “go-to” varieties of big, round, red tomatoes that are highly productive, feature balanced plant habits, and still deliver good tomato flavor. ‘Geronimo’ is a long-time standard, producing reliably hefty yields of 8–10 ounce, classic red slicers. ‘Bigdena’ is a more recent introduction, featuring slightly larger fruits than ‘Geronimo,’ with a taller fruit profile that affords the chef an extra slice or two. Both feature comprehensive disease packages and perform well in both the heated greenhouse and high tunnel. For a more compact plant habit, choose ‘Frederik’; it requires the least pruning and training, though most growers find the flavor a bit less sweet than the aforementioned ‘Geronimo’ and ‘Bigdena.’
Best All-Round Performer. The tomato variety that earns our highest rating for heated greenhouse production is ‘Rebelski’, as it’s known in Europe — also known as ‘DRW 7749’. ‘Rebelski’ has shiny bright-red, slightly ribbed fruits averaging 7–8 ounces, that are firm without being hard. It has excellent resistance to powdery mildew and leaf mold, which keeps the crop healthy over a long season. And, it has good flavor!
Hy-looms. For those who favor classic heirloom appearance and flavor, Johnny’s recent greenhouse tomato introductions include ‘Margold,’ ‘Marnero,’ ‘Marbonne,’ and ‘Cauralina,’ which together make up our French Heritage Collection. They look and taste very much like their heirloom counterparts — but with improved resistance to disease pressure and higher yield potential.
- ‘Margold’ preserves the look and flavor of the red-streaked yellow heirlooms, while adding leaf mold resistance, improving fruit uniformity, and improving marketable yield. Its very soft flesh has sweet and mild tomato flavor and thick, juicy texture, with an appearance similar to ‘Striped German.’ It’s a great BLT or burger-topping tomato.
- ‘Marnero’ keeps the best attributes of the black tomatoes, while again, improving upon disease resistance and yield. A dead ringer for ‘Cherokee Purple,” its flesh is also very soft, with the complex flavor and meaty texture you would expect from your favorite “black tomato” heirlooms. ‘Marnero’ stands out in Caprese salad, fresh pico de gallo, or any other preparation where raw tomato is the focus of the dish.
- ‘Marbonne’ represents the classic French ‘Marmande’ heirloom type, with rich scarlet skin and a crown accented by deep ribs. Because this type is so popular throughout Europe, there are actually several hybrids on the global market that resemble the original ‘Marmande,’ but we have found ‘Marbonne’ to be the best of the lot. It is very early maturing (as are most ‘Marmande’-types), and is the highest yielding of the French Heritage tomatoes. It is also arguably the sweetest and most universally appealing in flavor. There is no wrong way to prepare ‘Marbonne’!
The benefit to growers that the French Heritage tomatoes confer is in fruit with eating quality as high as the heirlooms but higher-yielding, due to better vigor and disease resistances than heirlooms, allowing the plants to live longer and stay healthier. By way of example, many greenhouse growers report heirloom yields of one-third to one-half of what they get off red greenhouse beefsteaks, which can be a money-losing proposition. With these tomatoes, we hope to help growers make money off their best-tasting tomatoes.
Another one of the best hylooms or heirloom “imitators” is ‘Pink Wonder’. It resembles the beefy pink heirlooms like ‘Rose’ and ‘Pruden’s Purple’ with smooth texture and flavor similar to those heirlooms — qualities that are uncommon in many modern hybrids.
‘Kakao’ is another recent addition to our line of greenhouse tomatoes, with a unique appearance and a flavor all its own. ‘Kakao’ has the black tomato look in a smaller package, with uniform, round fruits between 4½–5½ ounces. Its distinctive dark looks, soft flesh, and savory flavor — almost as though it had been sea-salted — make it well-suited to standout branding by variety.
UNHEATED Greenhouse or High Tunnel Production
For unheated greenhouse growing, we suggest the tomato varieties detailed below. For more information on unheated protected culture tomato production and relevant disease concerns, see our Top-15 Recommended Tomato Varieties for Hoophouse and High Tunnel Production, as there is overlap in the varieties as well as the conditions of protected-culture in these various structures.
The tomato varieties mentioned in the section above will also do very well in unheated greenhouses and high tunnels, but some growers find the seed cost to be prohibitive. For more “low-tech” indoor production, we often look to places like Italy and Spain for sourcing varieties. In these regions, tomatoes are grown in soil, under very large structures. The climate is hot and dry, so they don’t experience leaf mold very often. They breed primarily for resistance to soilborne diseases and viruses, as well as manageable plant habits. Resistance to verticillium, fusarium, nematodes, and TMV are so ubiquitous in these types that the term VFNT is used in the industry to describe this suite of traits. The markets these breeders serve are very fickle about fruit quality, so the flavor tends to be better in these types than in those bred for high-tech culture.
Recommended Favorites for the Unheated Greenhouse
‘BHN 589’ — A semi-determinate slicer with great all-around performance and a low-maintenance plant, ‘BHN 589’ is the variety we recommend trying first if you are getting into determinate tomato production under cover.
‘Estiva’ — ‘Estiva’ has been a fixture in Johnny’s catalog for a long, long time. We simply haven’t found anything else with its combination of production and quality. Bred for low-tech indoor production in southern France, ‘Estiva’ cranks out loaded clusters of remarkably uniform fruit in the versatile 6–7-ounce size range. The color is deep red and the flavor and texture are outstanding. ‘Estiva’ is very vigorous, but the plant habit is well balanced and thus highly suitable for unheated greenhouses. Resistance to soilborne pathogens and TMV are a nice added bonus.
‘Clementine’ —From Johnny’s classical breeding program, ‘Clementine’ is a unique orange cocktail tomato that matches well with the popular ‘Mountain Magic’. ‘Clementine’ features short leaves and a polite, open habit that fit well in close quarters and ventilate well.
‘Sunpeach’— A very tasty pink cherry tomato from Japan, ‘Sunpeach’ has leaf mold resistance and easy-access clusters hung on a well-behaved vine. Its unique color is perfect for mixed quarts.
‘Apero’ — Like ‘Sunpeach,’ ‘Apero’ is a small-fruited specialty that features leaf mold resistance and exceptional flavor. ‘Apero’ also has resistance to Fusarium, nematodes, and TMV, and a compact indeterminate plant.
‘Bolseno’ — Very similar to ‘Estiva’ in terms of habit, disease package, productivity, uniformity, and fruit quality, the difference in ‘Bolseno’ is that the fruits have a flatter shape with light ribbing, which some folks find more appealing on the farm stand. This tomato was originally selected as an Italian specialty — it can be harvested with green shoulders, like they do in Italy, but it can also be vine-ripened into beautiful crimson fruit. This is a “sleeper” variety — not everyone grows it, but those who do are devoted!
‘Granadero’ — A broad disease package, compact plant, and huge yields of blemish-free fruits make ‘Granadero’ an excellent choice for Roma tomatoes in just about any growing system, including unheated greenhouses and high tunnels. ‘Granadero’ was selected specifically for performing in organic systems, so you know it’s a tough customer. It features the VFNT disease package, with added resistance to powdery mildew, a problem increasingly seen in protected-culture tomatoes.
Grafted Organic Tomato Plants
For those looking to get a head start, we also offer growers an outstanding line of certified-organic tomato seedlings. These feature some of our favorite varieties grafted to ‘Estamino’ rootstock, so as to be more productive and disease-resistant. For greenhouse growers with limited time or opportunity for grafting, our professionally-grafted tomato plants can provide a very cost-effective solution.