Growing greens in containers

How to Grow Salad Greens

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Whether they’re called Buttercrunch, Little Gem, Tennis Ball, Bronze Mignonette, or Freckles Romaine, all salad greens start life as tiny black dots. Six weeks or so down the line, they’re a fresh salad on the table. And the crisp, chilly days of early spring are the right time to start planting these tender crops. “Lettuce is one of the easier things to grow,” says Charlie Mazza, a horticulturalist at Cornell University. The seeds need rich, well-drained soil (dark and moist, but not puddley), cool weather, and some light. Beyond that, “they are one of the more forgiving plants. They can even grow in a window box,” he says.
Growing Season
Lettuce is a cool-weather crop, and seeds can go in the ground about four weeks before the last frost. (If you live in a warm region, you can grow lettuce until the highest daytime temperature remains steadily above 80 degrees.) Check with your local county agent or State Cooperative Extension Office (the numbers are in the “Government” section of the phone book) for planting requirements; their websites often have answers, as well as links to the volunteer-staffed Master Gardener program. The U.S. Department of Agriculture’s site, gardening.gov, is also full of regional climate and soil information. Plan for your last harvest before it gets too hot. Most lettuce varieties go from seed to salad in 45 to 80 days. And if you sow seed every 8 to 10 days, you should have a constant supply all spring, even in a small space.
Soil
Till the soil well before planting. Because lettuce is one of the first things to go into the ground, the earth will probably be solid and inhospitable to small seeds. You can also use almost any container to grow lettuce. Just make sure it’s at least six to eight inches deep and has good drainage.
Seeds
Lettuce seeds are the size of pinpoints, so burying them too deep can make it hard for them to germinate. Check seed-packet labels for instructions. Scatter the seeds directly onto the ground; you will thin the plants as they grow.
Water
Depending on your climate and weather, water a few times a week or every day. Don’t let the soil get too dry or the plants will wilt. And don’t hose down lettuce until puddles form.
Fertilizer
You won’t need a lot of fertilizer (lettuce isn’t as demanding of nutrients as flowering plants), but make sure that any fertilizer you use is suitable for edibles. Look for the words “organic mix” on the label, or check with your nursery. Garden compost is a safe alternative.
Thinning
When leaf-lettuce plants are about one inch high, you can begin thinning and eating the lettuce. Use scissors to cut or snap off the shoots. This will prevent the roots of the remaining plants from being disturbed and give the plants room to thrive. To thin head lettuce, simply uproot the immature head. Keep thinning until plants are 4 to 10 inches apart, depending on the variety; head lettuce needs more space so it can form a ball.
Picking
When your lettuce is fully grown (check the information on the seed packet), pick it immediately and enjoy. During the growing season, you can sow new seed almost weekly so there will always be more on the way. When the leaves grow longer than four to six inches, you may find them too tough and bitter. So discard overgrown plants, which will make room for new seedlings.
The Four Categories

  • Crisphead
    The most famous variety (some chefs might say the most infamous) is iceberg, the tight, crunchy head you have probably eaten as a wedge, slathered with Russian dressing. Although iceberg isn’t as popular as it used to be, it is still the number-one seller in American supermarkets, and there’s nothing like it for giving a tuna-salad sandwich some snap.
    Growing tip: Of the four types of lettuce, crisphead is the most sensitive to heat. Without the right cool temperatures, the plants won’t form the proper tight shape.
    Other varieties: Wakefield Crunch and New York.
  • Butterhead
    If crisphead varieties are the tap water of the lettuce world, then butterheads, also known as Bibb lettuces, are the Evian. As the name suggests, their leaves are soft, tender, and slightly richer in flavor.
    Harvesting tip: Because their oval leaves are so bruisable, butterheads are ideal for the home gardener, who can show them more mercy than produce shippers can.
    Other varieties: Boston, Little Gem, and Buttercrunch.
  • Cos
    This variety includes that staple of the Caesar salad, romaine. Cos lettuce has a long, upright head and leaves with crunchy spines and a sharp flavor.
    Serving tip: Its texture makes Cos an ideal partner for limper, hard-to-fork baby lettuces and greens.
    Other varieties: Rouge d’Hiver, Cimmaron, and Paris White.
  • Loose Leaf
    These lettuces branch off from a single stalk. This means you can harvest a few leaves at a time while the plant continues to grow (head lettuce is an all-or-nothing proposition). Most grocery stores now sell bags of mesclun salad consisting of leaf greens, and many gardening catalogs sell mesclun seed packs: You sow the seeds, wait a few weeks, and see what comes up.
    Growing tip: Because they don’t form a head, loose leafs can tolerate warmer weather better than some of the other families, but they, too, grow bitter in the heat.
    Other varieties: Arugula (also known as rocket, and not technically a lettuce), red leaf, frisee, and Black-Seeded Simpson.
    Choosing a Crop
    For some armchair gardeners, the fun lies in studying seed catalogs. There is also a boundless variety of seeds available to home gardeners through nurseries, hardware stores, and the Internet. Consider the flavor descriptions and growing times when deciding which to plant. Look for heat- or cold-resistant varieties to suit your climate.
    Pests
    Slugs and snails can make lettuce look like lace, but don’t fight them with pesticides. Though slugs love lettuce, they like beer more. Set shallow containers of beer around the garden the slugs will slither in and drown. If necessary, protect lettuce from rabbits, deer, and other animal intruders by using fences, chicken wire, or all-purpose garden fabric ($10 to $19, gardeners.com).

8 salad greens to grow that aren’t lettuce

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I love making salads during the growing season. There’s nothing quite like walking out the back door with a pair of scissors or herb snips and harvesting your own salad greens. I even built a lettuce table for that very purpose. However I need variety. I’m not content to just grow one type of lettuce and call it a day. I grow a bunch of things so there is a medley of flavours and varieties in my bowl.

The thing is, you don’t have to be relegated to the lettuce section of the seed catalogue. There are so many other greens you can also grow. Here are a few of my favourites.

Growing different salad greens

Parsley: I absolutely love parsley. I know it’s often considered pure garnish, but I really enjoy the flavour and it’s great added to salads. If I’m out in the garden, I’ll pick a sprig (or three!) to munch away on. I like both flat-leaf and curly varieties. And last year, for the first time, I discovered swallowtail caterpillars munching away before they set up their cocoon business. Other herbs, like dill and cilantro (if you’re one of those people who doesn’t think it tastes like soap) are great mixed into a lettuce salad, as well.

I didn’t mind sharing my parsley (I plant more than I need) with the swallowtail caterpillars!

Amaranth: Niki is the one who introduced me to baby amaranth leaves. Last year I planted a lovely variety called ‘Red Garnet’ whose young leaves I harvested for salads.

Nasturtiums: When you think about it, nasturtiums are amazing flowers to have in the veggie garden. They not only attract pollinators and act as trap crops, you can eat both the blooms AND the leaves! The leaves have a bit of a peppery flavour and provide a nice flavour contrast when dispersed among a crop of sweeter lettuce leaves.

I love nasturtiums for their ornamental qualities and for all the wonderful edible and non-edible reasons mentioned above!

Baby kale: I’m one of those people who didn’t jump on the kale superfood bandwagon because I was already on it! I love steamed kale and make the odd batch of kale chips, but when you pick the leaves young, they are quite edible in a salad. And have you seen my crazy kale plant? One of my local restaurants makes a delicious kale Caesar salad.

My favourite kale variety is ‘Blue Vates’.

Pak choy: I find this Asian green to be crunchy and delicious and a perfect addition to or lettuce substitute. I have a packet from High Mowing Organic Seeds simply called White Stemmed Pac Choy waiting to go into the garden.

Sprouts: When I plant a row of beets, peas and sunflowers, I usually oversow (is that a word?) so that I can harvest the young seedlings for salad. Once I built my lettuce table, I deliberately planted a few rows for sprouts only! The beet ones are especially flavourful!

In this particular salad table planting, I have: escarole, ‘Red Sails’ lettuce, baby pak choy, ‘Lolla Rossa Darkness’ lettuce, ‘Tuscan baby leaf’ kale and ‘Red Garnet’ amaranth.

Swiss chard: I was harvesting Swiss chard well into the fall last year. Sometimes it was the only salad green I had to use at that point. I grow a variety – ‘Rainbow’, ‘Peppermint’, etc. All are delicious.

Spinach: This is a great crop for shadier areas and I love the flavour of the fresh baby leaves. Spinach will also tolerate a bit of shade!

How to Grow Your Own Salad Greens

Growing your own salad greens will put a world of fresh ingredients at your fingertips. Whether you are a gourmet salad lover who likes to experiment with interesting greens or someone who just wants to have your own homegrown lettuce, your choices are only limited by the seeds you can find and the space you have.

Types of Salad Greens

We always think of spinach and lettuce as the main spring greens, but there are many more to choose from. Look to the east—Asian greens such as napa cabbage, tatsoi, pac choi (or “bok choy”), mibuna, santoh, and hon tsai tai are especially suited to growing in cool spring weather. If you have never tasted any of these greens, then you are in for a treat. Some are hot and spicy, while others are quite mild. They can be eaten raw or cooked and will add flavor to any salad or stir-fry.


If you are lacking garden space, try growing salad greens in containers.

Depending on your taste buds, you can grow mild, tender greens like claytonia, chard, and mache, or bitter greens like endive, escarole, and radicchio. If you want to add a peppery tang to your salads, try mustard, mizuna, broadleaf cress, or arugula.

Lettuce is the obvious choice for a salad garden and there are many spring lettuces to choose from. Try a delicate butterhead, tasty heirloom crisphead, or colorful leaf lettuce. Plant them as soon as the ground can be worked. Lettuce seeds will germinate in soil as cold as 40°F (5°C).


Lettuce even grows great in a hanging basket!

“Cut-and-Come-Again” Greens

There are ready-made salad mixes that offer a wide variety of textures, colors, and flavors. Look for mesclun or misticanza mixes, or make up your own custom blend using seeds for your family’s favorite greens. Lettuces and greens that will continue to grow after being given a haircut are called “cut-and-come-again” in many catalogs.

Growing and Harvesting Salad Greens

The key to having perfect greens is to grow them under row covers, which help to keep them relatively clean and bug-free.

Many row covers are made from spun-bonded polypropylene, a material that is light-, water-, and air-permeable, and very lightweight. Most allow 70%-90% light transmission. Covers help to moderate temperature and give a few degrees of frost protection, too. They can be supported by wire hoops or just laid over the plants and held in place with rocks and soil. Unlike plastic, this breathable material won’t cook your plants on a hot sunny day.

One simple way to grow your cut-and-come-again greens is to rake the prepared seedbed smooth and broadcast the seed evenly or sow it in wide bands to make harvesting easier.

To keep a continuous supply of greens, plant a small section of the bed every two weeks. Cover the seeds lightly with soil and tamp down. Keeping the seedbed moist while the seeds are germinating is important and the row covers will help to keep moisture in. Greens are mostly water and will suffer a setback if allowed to wilt. When the plants emerge, keep the row covers in place and well-anchored on all sides. Only remove them when harvesting. This is a very effective way to foil flea beetles, the bane of the early spring garden. Tiny, black hopping specks no more than 2mm long, they will leave your lettuce riddled with small holes.

To pick your greens, carefully shear the young plants with scissors, leaving the growing center of the plant intact. Water and lightly fertilize the plants, cover them up with the row cover, and in no time at all, they will regrow and be ready for another harvest.

If you don’t have a lot of room, try growing salad greens in a pallet garden (pictured above). Wrap landscape fabric around the back and sides of a wooden pallet, then fill the openings with soil and plant your seeds or starter plants. When the plants have taken root and begun to grow, simply stand the pallet upright in a sunny location.

Turn just a small part of your backyard into a salad-lover’s dream garden and soon you’ll be harvesting a bounty of flavorful greens.

Learn More

Living in an urban setting, apartment, or very small space? See how to grow lettuce in containers.

See the health benefits of eating leafy greens.

Wondering what to do with your newly grown salad greens? Make one of these eight great salads!

Planted lettuce bowl. Photo courtesy Mischler’s Florist and GreenhousesRainbow Swiss chard. Photo from Mischler’s Florist and Greenhouses.

by Colleen Morrissey, herb manager and container designer at Mischler’s Florist and Greenhouses

If you love salad and enjoy gardening, plant a “lettuce bowl” container garden.

It’s a quick and easy project. You don’t need much space, so you can have a “lettuce bowl” container garden on a sunny balcony, front stoop or just outside your kitchen door. Setting the container on a picnic table or other tabletop may discourage rabbits, slugs and other pests.

This is also a project you can do with kids. When you get kids involved in growing and harvesting their own vegetables, they are much more likely to eat them!

Your container garden can look beautiful, too, because lettuce leaves come in so many different colors and shapes.

Lettuce is a cool weather crop grown primarily in spring and fall, but with successive sowing of seeds or biweekly planting of starter plants, the bounty can continue through the sunny months of summer. You should be able to harvest from one plant for a month or more.

Red salad bowl lettuce. Photo from Mischler’s Florist and Greenhouses.

Our modern selections of lettuce are the cultivated descendants of the wild Lactuca serriola, which is native to Asia, Eurasia and the Mediterranean. The earliest varieties were stalky with loose leaves, and eventually the ancient Romans bred them and “brought them to a head.”

Today there are hundreds of distinct varieties to choose from. Most are compatible with each other in growth habits and culture requirements, so you can be creative and mix several varities in one container.

The most popular greens for pots include the loose-leaf varieties: butterhead, mesclun, cos or romaine, kale, mustard and pak choi. As seen in the first photo, they can be interplanted with leafy herbs such as basil, parsley, cilantro, oregano, lovage and arugula.

When planting a a “lettuce bowl” container garden, have all your supplies ready.

Choose your planter. Lettuce has pretty shallow root system, so anything that is at least six inches deep will work. Your container can be anything you like—be creative.

Fill your container to the brim with a humus-rich, light potting mix, patting it down with your palm gently to level.

Green leaf lettuce. Choose plants for your “lettuce bowl” that are about the size of your thumb. Photo from Mischler’s Florist and Greenhouses.

Select a mix of seedlings, preferably an inch tall or thumb size. Water them well and let drain.

Next use a skinny spade to plant the seedlings a couple inches apart. They can grow quite happily in close quarters, so maximize the space.

Plant trailing herbs such as thyme or oregano along the edge so they can grow over the edge. Water thoroughly.

In a couple days the plants will perk up and start to take off.

If you want organic lettuce, make sure you start by mixing compost or humus into the soil. Fertilize with kelp meal or liquid seaweed, or the organic powders that come in a bag.

Lettuce will require a steady supply of moisture. Your plants will be bushy and ready for harvest in about a week to ten days.

Mesclun mix. Photo from Mischler’s Florist and Greenhouses.

Don’t just admire your plants; you need to keep culling or harvesting leaves to make space for growth. When you harvest, take the outer leaves of the rosette, leaving the growing tips in the heart center to keep producing new leaves.

If your container is getting crowded, try the cut-and-come-again technique. Cut off the leaves of an entire plant an inch or so above the soil and it will regenerate. You can do this to every other plant.

Now, you just need a nice dressing.

Maple Dijon Dressing, from Kitchen Explorers at pbs.org

  • ½ cup extra virgin olive oil
  • ¼ cup balsamic vinegar or red wine vinegar
  • 2 tbsp. pure maple syrup
  • 2 tsp. Dijon mustard
  • ½ tsp. herbes de Provence or dried thyme

Whisk all ingredients (or let your kids shake them vigorously in a jar) and store it in the refrigerator for up to two weeks.

Colleen Morrissey is herb manager and container designer at Mischler’s Florist and Greenhouses, 118 South Forest Rd., Williamsville. Mischler’s carries lettuce plants in six-packs and carries mustard and other gourmet or unusual greens in 3.5-inch pots.

All photos are from Mischler’s Florist and Greenhouses.

Salad bowls: Grow lettuce in containers

  • Potted lettuce loves full sun. Mix it with edible ornamentals such as violas. Potted lettuce loves full sun. Mix it with edible ornamentals such as violas. Photo: John Everett, For The Chronicle

Photo: John Everett, For The Chronicle Image 1 of / 5

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Image 1 of 5 Potted lettuce loves full sun. Mix it with edible ornamentals such as violas. Potted lettuce loves full sun. Mix it with edible ornamentals such as violas. Photo: John Everett, For The Chronicle Salad bowls: Grow lettuce in containers 1 / 5 Back to Gallery

Lettuce is a quick, nutritious fix for the winter-weary gardener hungry for a bit of green. Sow or transplant this easy, leafy cool-season vegetable February to April for a succession of healthy salad bowls.

We can plant lettuce in the garden in February, but for color and easy access, add a few pots of green and red varieties on the deck or patio.

Most any container will do — wheelbarrows, whisky barrels, window boxes or simple clay pots — as long as there’s good drainage. Lettuce roots are relatively shallow, but use at least a gallon pot that’s at least 6 inches deep.

Full sun is best, but lettuce will get by with less.

Getting started

Buy transplants: Pick up six-packs or 4-inch pots of transplants or seed packages from a nursery.

Fill pot with soil: Fill a well-draining pot to one inch below the rim with a nutrient-rich potting medium.

Sow seed: Sprinkle seeds 1/2 to 1 inch apart onto smooth, moist potting mix. Gently press in or cover with no more than an eight-inch of fine, light soil. Lettuce seeds need light to germinate.

::How many? You can plant about a dozen plants per person if you really like lettuce. Or if you’re doing consecutive sowings/plant two to four plants per person every two weeks. :: Spacing: Spacing is not an exact science when growing lettuce, especially when harvesting outer looseleaf types as they grow. You can space so plants, especially heading types reach full size. Or plant densely if going to follow the cut-and-come again harvest method. :: What fits? Basically, three smaller heading varieties can fit in an 8-inch pot; five to seven plants in a 12 to 15-inch pot. Nine to 11 heads in a 16- to 18-inch pot or 9-inch by 12-inch window box.

Water: Mist the area to prevent the soil from drying once the seeds are planted.

Check temperature: Best soil temperature for germination is 60 to 75 degrees. In ideal conditions, seeds may germinate in three days, but more often in six to 10 days.

Thin the crop: Thin seedlings according to lettuce type and harvest method. When seedlings are 2 inches tall, thin looseleaf types 3 to 4 inches apart if you’re going to follow the cut-and-come-again harvest method. Thin 4 to 6 inches apart if you wish to harvest more mature plants or if you’re growing heading types. Transplant thinnings to other containers or toss them into a salad. Thin again if needed.

Plant again: Make successive sowings every week or two for continued harvest.

Maintenance

Moisture: Maintain a moist soil. Dry conditions can mean a bitter flavor. Container-grown lettuce will dry out more quickly than those in the ground, especially in warm weather. Keep the soil moist but not soggy. Place saucers under balcony plants to avoid drips below.

Temperature: Plants also become bitter in heat. Refrigerate for a few days to break down bitter taste. To freshen wilted lettuce, wash it in cold water, shake it until fairly dry, cover it and refrigerate it for 12 hours.

Fertilizer: As soon as the lettuce is up, begin weekly applications of a foliar seaweed feed. To harvest, use sharp kitchen scissors to cut outer leaves when they are 3 to 5 inches long an inch or so from the soil line. Or cut the entire plant off about an inch from the soil line. It will regrow. Make successive plantings through the cooler days of spring for an extended harvest.

With a fertilizer-enriched soil mix, plants should have enough nutrients for about six weeks. Then apply a water-soluble, balanced such as a 20-20-20 fertilizer weekly or biweekly, depending on how much you water. Frequent watering leaches nutrients from the soil. Occasionally apply fish emulsion and/or a handful of compost per pot.

Harvest

Depending on the variety and weather, harvest within 30 to 60 days after sowing. Harvest in the morning while the leaves are crisp with sap. Cut or gently snip the outer leaves an inch or two from the soil line.

Types of lettuce

There are three types of lettuce for the winter-spring garden in our growing area:

Proven looseleaf varieties

Looseleaf is the easiest, quickest lettuce to grow. High in vitamins A and C and calcium, it’s harvested in 45 to 50 days from seed. You can plant more densely if you’re going to follow the cut-and-come-again harvest method since you’ll be removing outer leaves when they’re 4 or 5 inches long. Use sharp kitchen scissors to cut leaves about an inch above the soil line. Or cut all the leaves on a plant. They will regrow, giving you two to three harvests per season.

‘Black Seeded Simpson,’ a longtime favorite heirloom, has delicately flavorted, light green, crinkly foliage. ‘Deer Tongue’ is an heirloom with red-tinged, triangular leaves. Heat-resistant, sweetly flavored ‘Oak Leaf’ forms a tight rosette of medium-green, deeply lobed leaves. There’s also a ‘Red Oak Leaf.”Salad Bowl’ is a heat-resistant All America Selections winner with irregularly shaped leaves. ‘Red Sails’ has beautiful bronze-red leaves that intensify in color in cooler weather. ‘Vulcan’ is a a slow-bolting red leaf lettuce.

Butterhead lettuce

Butterhead or loosehead lettuce form a loose head of iron-rich, buttery leaves that are somewhat crunchier than leaf lettuces. A container 8 inches across is adequate for three butterheads; a 15-inch pot will hold five to seven plants.

Tasty butterheads include ‘Buttercrunch,’ a heat-resistant All America Selection; miniature ‘Tom Thumb’ and ‘Merveille des Quatre Saisons’ (‘Four Seasons’), a gourmet French lettuce with burgundy outer leaves and pinkish-cream inner leaves.

Romaine lettuce

Cos or romaine lettuce is a rather elegant lettuce with elongated, upright heads. The leaves are slightly coarser than leaf lettuces, but the inner leaves are especially mild and tasty. These lettuces contain good amounts of vitamins A and C and calcium.

Romaine types suitable for our gardens include ‘Paris Island Cos,’ a medium-green lettuce matures in about 75 days and ‘Rosalita,’ a deep-red romaine with crispy leaves that’s ready in 55 days. Space 8 inches apart to allow development.

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