I am serious when it comes to my tomato patch. I know I’m not alone in that sentiment. I’ve learned that maximizing soil quality and paying attention to my tomatoes daily will yield the best crop. I’ve compiled my hit list of the 9 most common tomato maladies to watch for since forewarned is forearmed!
- #1 Blights – the Quasimodos of Tomato Pathology!
- #2 Blossom-End Rot
- #3 Flower Dropsy
- #4 Fusarium and Verticillium Wilt
- #5 Bad Nematodes
- #6 Shiny, Sticky & Deformed Leaves
- #7 Sunscald
- #8 Tomato Skins Splitting or Cracking
- #9 Yellow Leaves
- Septoria leaf spot on tomatoes: More ways to prevent spots before your eyes
- Why Are The Leaves On My Tomato Plant Turning Yellow?
- What Causes Yellow Leaves On Tomato Plants?
- Yellow Leaves: Probably Nothing To Worry About
- What Should You Do To Prevent Tomato Leaves Turning Yellow?
- Is Your Soil Bad?
- Are You Watering Too Much?
- Other Reasons Why Tomato Leaves Turn Yellow
- Leaves Turning Yellow? Don’t Overreact!
- Yellowing tomato plant leaves
- What makes tomato plant leaves yellow?
- Why are my tomato plants turning yellow on top?
- Why are tomato plant leaves turning yellow and brown?
- Related posts:
#1 Blights – the Quasimodos of Tomato Pathology!
Early Blight is a fungus that survives the winter on old vines and then rears its ugly head on your new plants. You will know it’s Early Blight when you see blackish-brown spots on the leaves, leaf drop off or see “sunburned” fruit. The best solution is to clean up old vines when the season ends, dispose of in the trash and don’t add it to compost pile. Rotate your planting areas and space the plants to allow for good air circulation.
Late Blight starts with leaves that appear water-soaked later turning brown and papery. The fungus is normally present when the weather is very wet enabling the spores to travel far infecting large areas. Like Early Blight, Late Blight is also preventable by rotating your crops annually and by maintaining good air circulation around your plants. If you think that you have Late Blight, same treatment – discard infected plants in the trash and don’t compost.
#2 Blossom-End Rot
Blossom end rot sounds like it should be terminal, but a tomato plant can usually pull itself out of this nosedive. The rot looks like pale, brown spots that turn black and flatten the bottom of the fruit due to a lack of calcium or uneven moisture. Lesson is, reduce extreme swings in moisture – avoid allowing them to wilt or overwatering tomato plants. If you don’t think fluctuation in moisture is the cause, get your soil tested. Too much nitrogen or soil that is too acidic or alkaline will limit the plant’s ability to absorb nitrogen. Lime will sweeten the soil and composted leaves will make it more acidic. Use a fertilizer that is low in nitrogen and high in phosphorous.
#3 Flower Dropsy
Flowers that form but drop before fruiting indicates that your weather is fluctuating too much. If the nighttime temperatures drop below 55Â°F or if the daytime temps are higher than 95Â°F with nighttime temperatures that don’t drop below 75Â°F, this can trigger blossom drop. Hot drying winds can intensify the problem. If the plant is not blooming during these periods, you have nothing to worry about however, if your flowers are dropping mulch to maintain moisture.
#4 Fusarium and Verticillium Wilt
No, this is not the next zombie movie the ‘tweens are watching. Both of these wilting conditions are caused by an incurable fungal infection – sadly, it’s just as deadly as being stuck in a Night of the Living Dead. Once a plant has either one, you should dispose of the plant immediately, do not add to the compost pile. Fusarium Wilt makes the leaves on one branch of the infected plant start wilting and yellow. Verticillium Wilt is yellowing between the major veins on mature leaves. Next year, select a tomato variety that is resistant to wilt.
#5 Bad Nematodes
Yikes! Like a ghost, this varmint is virtually invisible. Resembling some creature from the Black Lagoon – these microscopic eelworms are soil-born, so there is no “cure” for them. They infest the roots causing them to swell. The only aboveground symptoms are stunted plants and discolored leaves. Fortunately, your tomato plants will still bear edible fruit, but once you’ve discovered the culprit, you will have to wait to address the problem. A common fix is to simply plant marigolds to repel them.
#6 Shiny, Sticky & Deformed Leaves
Shiny, sticky & deformed leaves – no it’s not the name of your child’s garage band. It’s the usual calling card from an aphid, whitefly or spider mite attack. Ghoulish aphids suck the plant sap and excrete a sticky substance on the leaves and fruit. Look for the small, pear-shaped insects congregating on the top growth or on the undersides of the leaves. They can be green, yellow or blackish. Spider mites make small yellow specks and spin fine webs on the leaves, making them feel sticky. Whiteflies will fly up like a cloud when you brush the plant. Keep your tomato plants well-weeded but to overpower them you need reinforcements from a horticultural soap.
Sunscald is what we all get when we sit exposed and unprotected for hours outdoors not being sensible about our UV ray absorption. Happens to tomatoes too! Your tomatoes may show yellow or white patches facing the sun. To prevent sunscald grow them in cages where they will produce protective foliage.
#8 Tomato Skins Splitting or Cracking
Not pretty but definitely the lesser of the other 8 evils mentioned here because the fruits are still edible. Cracking or splitting happens because of sudden growth spurt from an increase in moisture after a dry spell. It can also occur when the fruit is overripe. Provide even moisture and choose plant varieties that are less prone to cracking. Cherry tomatoes are the guiltiest so pick them when they are ripe or almost ripe and/or just before a predicted rain storm to prevent cracking.
#9 Yellow Leaves
Yellow leaves, depending on where you are in the summer season can spell trouble, or not. Late in the season, it’s just the tomato shutting down. If early on in the season you notice yellow, uncurled leaves at the bottom of the plant that work their way up – that can signal a nitrogen deficiency or leaves turning yellow or brown higher up on the plant could be early blight.
It’s best to do a soil test to determine if it is a nitrogen deficiency. Depending on the soil test result, you may need to supplement the soil with well-rotted manure or compost, both of which are high in nitrogen. You can also apply a nitrogen-rich organic vegetable fertilizer.
Next year, proper soil preparation prior to planting, with good organic material or compost, will prevent this condition.
Good to Know
For a comprehensive reference for the other 99-problems that can happen with tomatoes, see the Guide to the Identification of Common Problems divided into these seven categories: Tomato Disorders, Green Fruit, Ripe Fruit, Insect Pests, Leaf, Stem and Root — full of imagery to help further diagnose your tomato troubles. Please go to http://aggie-horticulture.tamu.edu/publications/tomatoproblemsolver.
Disease has worked its way nearly to the top of these tomatoes.
Q: I’m having a problem with my tomato plants. The leaves are getting spotted, turning yellow and dying from the ground up. It seems to be working its way up the plants. Is there any cure for this?
A: That sounds like septoria leaf spot, which I’ve seen getting worse and worse these last 10 years or so. It’s a disease caused by a soil-borne fungus that overwinters in the soil.
Once you get it, it’s hard to eliminate. Spores splash up on stems of new plants, and when the weather turns humid in summer, the disease really takes off. It can kill whole plants by late summer and detract from the taste of the fruit in the meantime.
There’s no cure. I think the most effective control is to spray plants with a fungicide every 7 to 10 days at the first sign of any spots. That’s usually right about the time the first fruits start setting.
Daconil (chlorothalonil) is effective if you do chemicals, and liquid copper is the organic option. There’s also an organic spray called Serenade that might help, although it’s expensive and didn’t work that well for me.
You can slow the disease by picking off infected leaves and by staking the plants and pruning some of the excess branching to help air flow dry the leaves better.
In the long run, try putting down a fresh coat of straw or leaf mulch at planting to discourage spores from splashing out of the soil onto the stems.
Some people say they’ve had luck watering plants every 2 to 4 weeks with aspirin water (1 aspirin dissolved in a gallon of water), which supposedly stimulates the plants’ immune system. I didn’t see much difference when I tried it.
Others try biofungicides such as Actinovate, Root Guardian or Root Shield, which are “friendly fungi” that feed on the disease-causing fungi. These are expensive, too, and I didn’t notice any benefit the year I tried Actinovate on my tomatoes.
It also helps to water the soil, not over top of the plants, which wets the leaves and encourages the growth of septoria.
At the end of the year, remove all plants and any infected, fallen leaves, as well as any weeds that might harbor the disease (especially ones in the nightshade family). Since the disease can overwinter on stakes and fences, spray them with a bleach solution (9 parts water to 1 part bleach) before planting a new crop.
Some tomato varieties are slower to get septoria than others, but I haven’t found any yet that are completely resistant. ‘Big Beef’ does as well as any for me. Most of the heirlooms I’ve grown (usually the tastiest ones) seem to get this disease pretty readily.
Septoria leaf spot on tomatoes: More ways to prevent spots before your eyes
Editor’s note: Tomatoes are susceptible to several diseases in the summer. To help you identify whether your tomatoes are infected with Septoria leaf spot or another disease, see the tip sheet “Tomato Diseases in the Home Garden.”
Tomatoes are one of the favorite fruits or vegetables gardeners grow every year. They are unique in several respects. Botanically, the tomato is a fruit. It is classified as such because the portion that is eaten contains reproductive structures (seeds). However, in 1893, the tomato was declared a vegetable by the United States Supreme Court. The reason involved the collection of import duties. So, the tomato is either a fruit or a vegetable, depending on whose definition is used.
The tomato was called the “love apple “and believed to be poisonous until around 1850. It was only grown for its attractive but forbidden fruits. Because it is in the same family as nightshade, it was considered unsafe for human consumption.
Regardless of its interesting history, almost all gardeners include a tomato or two for their eating pleasure. Michigan summers with their warm and often humid climate are favorable for various leaf blights to develop. One of the common tomato maladies is Septoria leaf spot. It is a fungal disease that affects the leaves, but not the fruit. The first leaves that are affected are typically toward the bottom of the plant. The leaves develop small, dark spots that rapidly enlarge to 0.25 inches and have a tan or gray center. There may be small, black dots, which are the fruiting bodies of the fungus, located in the center of the spot. If there are enough spots, the leaves turn yellow, then brown. The leaf eventually wilts, dries up and falls off. The Septoria pathogen will then spread via water splashing to the upper leaves causing defoliation further defoliation. Michigan State University Extension hotlines are just beginning to answer questions about Septoria now.
Left, Signs of Septoria leaf spot on a tomato leaf. Photo credit: William M. Brown Jr., Bugwood.org.
Right, Leaf spotting and advanced decay of Septoria leaf spot. Photo credit: Paul Bachi, Univ. of Kentucky Research and Education Center, Bugwood.org
Septoria can be prevented but not cured once it is evident. If Septoria has been a problem on tomatoes in previous years, it may become an issue in subsequent years especially if the tomatoes are always planted in the same garden spot each year. The pathogen survives best on tomato foliage but may also infect Solanceous weeds related to tomatoes like Jimson weed, horse nettle, ground cherry and nightshade. When conditions are wet, spores are exuded from the Septoria fruiting bodies present on the infected tomato leaves. Once the spores land on a healthy leaf, spotting can appear in five days if weather conditions are ideal.
There are a number of cultural techniques that can be used to limit Septoria. Picking off the spotted leaves can slow down the disease if the infection is fairly light. Growing tomato plants in containers can be especially helpful provided that the soil used in the container is not from the garden. Using a commercially available bagged potting mix assures you that you’ll be starting your plants in a fresh environment free of residual Septoria. Remember to stake and space the tomato plants so that air can move freely within the foliage so that the time that the tomato leaves are wet is minimized. Water the plants via trickle irrigation so as to keep the foliage dry. If watering the plants overhead, do it at a time of day that allows the foliage to dry quickly. Avoid watering the plants in the evening as that might allow the leaves to stay wet through the nighttime and that will favor disease. If your garden is large enough, rotate your tomato plants so they are not grown in the same spot each year. At the end of the season, remove any infected tomato debris and dispose of it (do not compost it).
If despite your best efforts, Septoria continues to make a yearly appearance in your garden, you may want to consider using a protectant fungicide. One of the most common fungicides used for tomato spots/blight is chlorothalonil which can be found in several brands. There is now an organic fungicide called “Serenade” that can also be used. It may be difficult to find unless there are local businesses that carry organic products or it may have to be purchased online. Always read and follow all the label directions. It usually indicates that the spray is repeated at seven- to 10-day intervals during the growing season to protect the plant. During rainy periods, the interval between the sprays may need to be shortened. (i.e., applications made every 7 days versus 10 days). However, pesticide sprays cannot be applied more frequently than what is specified on the label.
By following these growing strategies you should be able to minimize Septoria leafspot. Your bacon, lettuce and mayonnaise will thank you.
Thanks to MSU plant pathologist Mary Hausbeck for review and input to this article.
A lush green yard can represent a major monetary investment in the value of your home. For this reason, when you discover tomato leaves turning yellow it can be extremely disappointing. Why do tomato plants turn yellow all of a sudden and start dying?
- What causes this?
- Do you just have poor soil?
- Are your gardening care practices wanting?
In this article, we will explore these questions and provide some sound advice on proper soil amendment and good plant care practices to help you keep your green plants green. Read on to learn more.
Why Are The Leaves On My Tomato Plant Turning Yellow?
Many gardeners enjoy growing tomato plants, which often thrive without much attention, especially when planted in places with plenty of sunshine and water.
However, tomato plants can easily succumb to a number of problems, landing their caretakers in a world of despair. Considering all their trouble, it’s a wonder many people still grow them.
What Causes Yellow Leaves On Tomato Plants?
Why are leaves turning yellow on tomato plants?
Well, tomato plant leaves turn yellow for a number of reasons. However, yellow tomato leaves don’t necessarily mean that the plant is failing.
Tomato plants that turn yellow on their stems, leaves, or fruits may suffer from a pest infestation, disease, or extreme temperatures, which can ultimately affect the quality of the yield.
Some situations can also lead to yellow leaves on tomatoes, such as nitrogen deficiencies in the soil, over watering, under watering, or insufficient sunlight on the bottom leaves.
Let us look at each of these causes, and hopefully, you will find one or a combination that could help you come up with a proper solution.
Yellow Leaves: Probably Nothing To Worry About
Yellow leaves at bottom of tomato plants are not necessarily a call for trouble.
The lower leaves on a large, bushy, mature plants may display brown spots, might not receive sufficient sunlight, causing them to turn yellow. This is really nothing to worry about.
Fungal diseases like:
- Early blight
- Late blight
- Blossom-end rot
- Tomato yellow leaf curl virus
- Verticillium Wilt (treatment)
- Fusarium Wilt (treatment)
… all usually cause yellowing.
The ‘yellowing’ starts from the lower leaves, making their way up to the top of the plant. When these tomato diseases are left untreated, the plant may eventually die.
Wilt diseases mostly thrive under wet conditions and hosted by nearby weeds. You can control wilt diseases by regularly applying fungicides to your tomato plants. When the problem persists, you should consider using wilt resistant cultivars for future projects.
Related Reading: Learn more about Leaf Spot Alternaria here.
Pests such as the Psyllid insect and tomato hornworms usually feed on the leaves, and in the process, inject toxic saliva into the plant, causing the leaves to turn yellow. Stems might also become crooked, and the leaves develop purple tinged veins.
To confirm a psyllid infestation, check the leaves’ underside for nymphs. To prevent the problem, it’s recommended to dust the foliage with Sulfur. A spider mite attack could also cause yellow striplings on the leaves. An insecticidal soap can help alleviate the problem.
Insufficient nitrogen in the soil
You also need to check the amount of nitrogen in your soil. Nitrogen is essentially the element that gives plants the dark green color, and enhances healthy growth.
Nitrogen deficiency in the soil will cause the leaves of plants (including your tomato plants) to turn yellow or gain spots.
Test the amount of nitrogen and other nutrients in the soil, but be careful not to add excess nitrogen, as it could actually “burn” the plant.
Too much nitrogen could also make your tomato plants to be bushy and beautiful, but bear no fruits.
Heat is also a culprit when it comes to yellowing in leaves and fruits. This is commonly referred to as “solar yellowing” or “yellow shoulders”.
Yellow shoulders usually occur when the fruit are beginning to ripen, followed by a rise in temperatures above 86 degrees Fahrenheit.
Half of the tomato fruit ripens into red, while the upper half turns yellow. In exposed, hot locations, sunscald may occur, causing the fruit to turn white or yellowy, with a sunken-in leathery appearance.
Yellow leaf tomatoes caused by heat usually occurs when the plant lacks enough leaves to protect the plant.
To prevent this, control and monitor foliage harming tomato plant diseases such as the Curly top virus, and the Ring top virus.
The virus will actually show signs of yellowing leaves that tend to curl upwards. Also, leave plenty of leaves on your tomato plant when pruning.
Tomatoes are also sensitive to cold. Cool and rainy climates could thicken the lower leaves, which will in turn roll.
However, this is a stress response that doesn’t cause permanent damage or interfere with fruit production. New foliage will grow in warmer weather, and the plant won’t be affected.
How much are you Watering?
If the plant does not receive adequate water, its yellow leaves can start at the bottom of the plant. Tomato plants require watering especially when they are young seedlings or after they are transplanted into the garden.
The tomato plant will also require watering during the hot seasons, especially when the plant is bearing fruit. In most case, a good, deep watering a day will do when bearing fruit, or in hot temperatures.
Be careful since over-watering can actually cause leaves to turn yellow at the bottom. At times, this can be hard to control, especially in rainy areas.
For this reason, it’s imperative that you have a good mulch around your plants, and use well-draining soil that doesn’t develop puddles when watered. If drainage is an issue, a transplant mix or compost can help.
What Should You Do To Prevent Tomato Leaves Turning Yellow?
As soon as you pick up the plant from the nursery, you should start a pest and disease prevention routine. Be sure to look for dark green, stocky plants with thick, stiff stems and no signs of leaf spotting or yellowing.
Don’t purchase any plants already flowering or bearing fruit, since they have a harder time adapting to the new home than younger plants. In general, tomatoes will do well in a minimum of about 6 hours on direct sunlight.
You should also allow about 2 feet spacing between small plants, and for the larger plants, spacing should be up to 4 feet. This is essential as it allows air to circulate between the plants and through the leaves, which helps to prevent fungus.
When possible, water the plants from the base, preferably using either a watering can or a drip irrigation system.
For regular sprinklers that water the entire plant, do the watering in the morning to allow the plants to dry out before sun down.
You can also prevent infections by choosing the proper type of tomato, as many are resistant to some fungal infections.
Now let’s look at some general reasons there are yellow leaves on plants.
Is Your Soil Bad?
Very often, inexperienced gardeners and first time cannabis growers write off their poor plant performance to poor soil conditions. While this may be a part of the problem, it’s important to understand that poor soil conditions can certainly be corrected.
If your soil:
- Lacks in nutrients
- Holds an unusually high pH level
- Drains poorly
… you can expect your plants to suffer; however, you can also reasonably expect to be able to correct these problems.
Very hard and compacted soil (such as clay soil) should be well tilled and amended with compost to improve drainage and reduce soil compaction.
Once the basic soil has been treated in this way, remember that when you add new plants and trees, you should dig ample and generous holes and fill them with a loose mixture of your native soil, compost and your chosen organic or chemical fertilizer.
Tomato Tip: We always plant tomatoes with Epsom salts in the planting hole
When you start your plants off with a loose, rich, well-drained soil you give them a much better chance of thriving. Once your plants become established, add a gypsum soil enhancer a couple of times a year to keep the soil in good condition.
Are You Watering Too Much?
Remember that yellowing leaves is one of the basic symptoms for lack of calcium. If you water too much, you will wash the calcium away from the soil and prevent your plants from being able to take up enough calcium to thrive.
To prevent this problem, you must learn how to water properly. It is tempting to water very frequently and lightly; however, this is exactly the wrong way to do it. Instead, learn to water infrequently and deeply.
By allowing the soil to become slightly dry between watering and then watering slowly, over an extended period of time, you encourage the plants’ roots to stretch out in search of water. This helps your plants establish themselves more quickly and with a lesser amount of stress.
Just keep in mind that if you see your plants’ leaves beginning to yellow or becoming yellow with green veins (chlorosis) you should resist your immediate impulse to water.
Over-watering will only make these conditions worse. Instead, you must establish a regular watering schedule (weekly is good) and apply soil amendments on a regular basis.
Note that if your plants are experiencing chlorosis, you may wish to give them a dose of a chelated iron supplement; however, you must remember that your soil needs to have good nitrogen content in order to activate iron supplementation.
If your soil is very compacted and has a high clay content, you may also wish to amend it with soil sulfur a couple of times yearly to reduce its acidity.
Other Reasons Why Tomato Leaves Turn Yellow
What causes yellow leaf on tomato plants?
In addition to soil and watering problems, there are a few other reasons for yellowing leaves on tomato plants. Among them are:
- Infectious diseases such as bacteria and fungus may cause your leaves to yellow.
- Insect pests may suck the life out of your plants and cause yellowing.
- Excessive fertilizer may burn the plant leaves and cause brown spots and yellowing.
- Inadequate lighting can interfere with photosynthesis.
- Excessive heat or cold can cause tomato plant yellowing.
Leaves Turning Yellow? Don’t Overreact!
What causes tomato plant leaves to turn yellow?
Remember that leaves do naturally turn yellow as they mature, age and prepare to fall off. Occasional yellowing of leaves is nothing to be concerned about. If you do notice your tomato leaves yellowing rapidly and en masse, refer to the tips presented here to correct the problem.
Yellowing tomato plant leaves
Your first problem is ‘early blight’ and the second problem is spider mites. These are very common problems with tomatoes. There are 2 cultural situation you need too look at:
1. Is the soil too rich? You did not say what the ratio of sand to compost/manure is. Too much compost may be part of the problem. But I sure see good tomatoes in the picture. One sign of too rich a soil is good growth but poor tomato production.
2. No cover over the soil. This is very important too cut down on splashing soil which creates wounds for fungus to enter the plant, to keep the moisture even and temperature of soil cooler, to keep water from disturbing the soil.
Tomato plants are developing brown spots on the lower foliage. This is the result of a fungus infecting the foliage causing a disease known as early blight. Early blight is an annual problem for most gardeners. It normally develops into a problem when plants have a heavy fruit set and the area has received rainfall. Spores from the fungus are spread to the lower foliage by wind and splashing rain and soil. Leaves must be wet for infection to occur. At 50 degrees F. the leaves must be wet for 12 hours for infection, but at temperatures above 59 degrees F., the length of time for infection is only 3 hours. Leaf spot development is most severe during periods of cloudy days and high humidity. To control the fungus, remove and destroy all the infected leaves so the disease is not spread from spores on the infected leaves, keep rainwater and irrigation water from splashing by keeping a layer of straw or some other mulch under the plants and keep irrigation water off foliage. A foliage applications of a fungicide must be made every 7 days until moist conditions (dew included!) no longer exist. Several applications are necessary.
Thoroughly read and carefully follow all pesticides directions.
Go To the tomato problem solver on Aggie-Horticulture http://aggie-horticulture.tamu.edu/publications/tomatoproblemsolver/
Spider mites are common pest problems on many plants around landscapes and gardens. Injury is caused as these insects use their sucking mouth parts to feed on the sap. The mites are on the underside of the leaves. Damaged leaves appear as mottled or speckled on the top of the leaf caused by sucking out the chlorophyll with the sap.
Severe infestations cause leaves to discolor by producing a gray, silver or bronze appearance to the leaves. Spider mites cause serious stress to plants. Infestation is worse during dry hot weather.
Spider mites are a type of arachnid. Spider mites are tiny. Hold a white sheet of paper under an infested leaf. Tap the leaf. Watch the debris and if you see tiny red insect crawling, these are spider mites.
Large population will produce webbing. Webbing protects the mites and their eggs from natural enemies and unfavorable environmental conditions.
The most damaging spider mite is the two-spotted spider mite (Tetranychus urticae). This mite attacks a wide range of landscape plants, including many vegetables particularly tomatoes
Adequate moisture of plants during dry conditions will help limit the stress that creates the condition favorable for spider mite outbreaks. Periodic hosing of plants with a forceful jet of water can physically remove and kill many mites, as well as remove the dust that collects on foliage and interferes with mite predators. Disruption of the webbing also may delay egg laying until new webbing is produced. Sometimes, small changes where mite-susceptible plants are located or how they are watered can greatly influence their susceptibility to spider mite damage.
· Natural enemies include small lady beetles, predatory mites, minute pirate bugs, big-eyed bugs and predatory thrips.
· One reason that spider mites become a problem is insecticides that kill their natural predators.
Call your Extension office for the names of the fungicide and miticide they recommend.
Washington County Extension
Tomatoes are very appealing to grow in a garden or a greenhouse. However, there are tomato troubles you have to be aware of. For example, while checking your plants in the morning you can find out that someone ate your tomatoes at night!
There are many reason why tomato plant leaves are turning yellow. However, if you notice that tomato leaves are tuning yellow and identify the reason why early, it is easy to fix this problem.
What makes tomato plant leaves yellow?
Reason 1 – It is absolutely normal for mature plants. A few lower leaves on a mature tomato plant can turn yellow sometimes, dry out and fall eventually.
Reason 2 – Underwatering causes yellow leaves on tomato plants. If the leaves look dry and are crunchy when you touch them, you need to water them more.
It doesn’t necessarily mean that you are not watering your plants enough, it might be due to poor drainage. The soil should be well-drained. Sometimes when you are watering the plants water might not be reaching the roots resulting in the waterlogging of the plants.
If underwatering and waterlogging are present, you need to improve the soil drainage. Start using sand or planting in raised beds, also, you can use compost or transplant mix.
Reason 3 – Overwatering is the most common reason why tomato plant leaves are turning yellow. If the leaves are yellow and limp, it means that you water your plants too much.
If you noticed yellow leaves on the plant, check the soil first – is it dry or soaked? Water tomato plants the most when transplanting them into the garden as well as when they are very young seedlings.
Soak tomato plants once every 5 to 7 days. Let the soil dry before watering and make sure the soil is not left soggy. It is important to water tomato plants at the base of the plant and avoid the leaves. The best time of the day to water tomatoes is early in the morning.
On the hot days you need to water your tomato plants once a day. Make sure to have one deep watering daily. It is also applicable to the plants that are bearing fruit.
Reason 3 – The cause for yellow leaves can be the lime compost. If upper leaves of tomato plant are firm and yellow it can be due to lime added to the compost. Also, if you use hard water on lime-hating plants, it can yellow leaves. Opt for lime-free compost to solve this problem.
Reason 4 – Cold droughts lead to leaves turning yellow. If you noticed that several tomato plant leaves turn yellow simultaneously and the fall, it is likely due to cold droughts.
Reason 5 – Yellow spots or patches on the leaves are signs of the viral infection. The plant could be bought already contaminated with infection. Alternatively, the viral infection was carried to the plant by an insect. Unfortunately, you can’t cure viral infections. However, you can get rid of the tomato bugs to prevent them from spreading viruses.
Reason 6 – Lack of sunlight on mature plants leads to bottom tomato plant leaves turning yellow. When the plant matures it becomes bushy and the top leaves can block the bottom leaves getting sunlight. This often leads to yellow leaves but it is totally normal.
Reason 7 – Nutrients deficiency results in yellowing. It is also known as chlorosis. Leaves don’t produce enough chlorophyll which is responsible for the green color of the leaves.
Chlorotic leaves are usually pale, yellow or yellow-white. Lack of nutrients in the soil means that plants don’t get enough nutrients to synthesize chlorophyll. As a result, leaves are turning yellow.
The most common nutrient deficiencies in plants are iron, nitrogen, magnesium and zinc. The type of yellowing helps to determine what nutrients the plant is lacking. For example, if areas between the veins of the youngest leaves turn yellow, that is the sign of iron deficiency.
Why are my tomato plants turning yellow on top?
If you noticed that tomato plants are turning yellow on top, that is most likely due to tomato diseases or pests present in or around the plants. For example, infection with Ringtop virus can cause leaves yellowing to be spreading upward. In addition, if yellow leaves are curling up as well, it can be caused by a tomato yellow leaf curl virus.
Why are tomato plant leaves turning yellow and purple?
There are 4 main reasons why tomato plants leaves are turning yellow and purple:
- Temperature fluctuations – Tomato plants require warm temperature (at least 50° F) and planting in a cold greenhouse will lead to young plant leaves turning purple.
- Phosphorus deficiency – it is the most common reason why veins of tomato plant leaves are turning purple or the whole leaf turns purple.
- Infection with leaf curl virus – the symptoms can differ by plant but most of the time tomato plant leaves are curling, the leaf veins are becoming purple and the leaves are turning yellow.
- Infestation with psyllid pests – the affected tomato plant leaves are turning yellow and the veins purple along with the upright appearance to the leaves as a result of the disease known as psyllid yellows.
Why are tomato plant leaves turning yellow and curling?
There are two reasons why tomato plant leaves are turning yellow and curling: underwatering and viral diseases. Crispy to touch yellow leaves with a slight curl are a sign of watering problems. On the other hand, a geminivirus known as a tomato yellow leaf curl virus transmitted by whiteflies causes tomato leaves to turn yellow and to curl upwards.
Why are tomato plant leaves turning yellow and brown?
It is most likely that tomato plant leaves are turning yellow and then brown because the nutrient deficiency got more severe. Generally, if you notice that the leaves have yellow or brown spots, test the soil to find out which nutrient the plant is missing.
Should I remove yellow leaves from tomato plant?
You should remove yellow leaves from tomato plants to prevent them from becoming a sugar drain on the rest of the plant. Also, removing yellow, dry leaves helps to increase the fruit production. Remember that dead plant material on the soil promotes mold development.
Can yellow leaves turn green again?
Will yellow leaves turn green again depends on the reason why leaves turned yellow. If it was due to nutrients deficiency and you fixed it right away, there is a high chance that yellow leaves might turn green again.
However, if it is a mature plant and leaves are old, yellowing is just a stage before falling off. Generally, it is better to remove leaves which are half way yellow as these can’t turn green again. Crispy and necrotic plant tissue is, unfortunately, not able to recover.