All About Garden Greens

Make garden greens the backbone of your year-round garden with these tips.

Spinach

Spinach is the ideal crop for the cool weather garden, and makes for one luxurious salad.

Photo by Fotolia/Dionisvera

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Garden greens

Greens are the backbone of my garden. Sure, I love the taste of a tomato picked off the vine and warmed by the sun, but I typically have to wait until July for that. And, yes, I rely on squash and root crops to sustain me through the winter. But greens from my Zone 5 garden provide food year-round. I can harvest salad and cooking greens from early spring to early winter, and when the ground is covered with several feet of snow, I use frozen and dried greens I put up earlier. From cabbage to collards, and arugula to orach, greens offer an incredible diversity of flavors, colors and textures. Welcome to the wide world of garden greens.

How to grow lettuce

Lettuce is a cool-weather crop that prefers moist soil to thrive. Since germination can occur at temperatures as low as 40 degrees Fahrenheit, lettuce is ideal for early spring plantings as well as for the fall garden. It will survive a light frost if sufficiently hardened and can handle temperatures as low as 20 degrees — lower with adequate row cover.

Ideal growing temperatures, however, are between 60 and 65 degrees, although lettuce can certainly be grown into the warmer months if certain protections are put in place, including adequate shade and heat protection. Reemay garden blankets and shade cloths are good options with proper ventilation.

Succession planting is often recommended, so if you sow seed every two to three weeks, you will have lettuce emerging throughout the growing season. This only works, however, if the environmental conditions are relatively constant. More often, the later plantings catch up, and you end up with a huge amount of lettuce maturing at the same time. I prefer planting several varieties at one time and repeating this every couple of months. The different varieties grow at different rates and provide many months of harvest.

Lettuce can also be used as a “cut-and-come-again” crop. If an inch or more of growth is left after cutting, the plant will regrow. Under optimal growing conditions, one plant can be harvested several times.

The spinach family

Spinach requires cool temperatures — between 40 and 75 degrees for optimal germination — and bolts readily in warm weather. The beauty of spinach, though, is that it has a strong tolerance for cold weather, with young plants surviving temperatures as low as 15 degrees. In cool, moist soil, spinach can be treated as a cut-and-come-again crop.

A relative of spinach, Swiss chard is grown for both its leaves and stems. You can almost think of it as two vegetables in one. Chard differs from spinach, though, along with cousins beets and amaranth, in that it can tolerate hot weather. It will germinate in temperatures up to 95 degrees and can withstand extended summer heat under partial shade.

Brassicas

Leafy brassicas star in many cuisines: from Southern-style collard greens, to German sauerkraut, to stir-fries of bok choy. This family of flavorful greens includes arugula, cabbage, kale, collards, mustard and most Asian greens, not to mention turnips and radishes. Brassicas often have a tougher texture than other greens and withstand a greater range of growing temperatures.

Kale is one of my favorite brassicas. It produces tasty, healthy greens for much of the year. In fact, kale is sweeter and more tender after a hard frost. In Zone 5B, I can overwinter kale if it’s mulched with straw. Collards are the Southern cousin of kale.

Mesclun and other mixtures

One seed packet provides a diverse mix of greens you can harvest for months. Sounds great, doesn’t it? But, like many things, mesclun seed mixtures work better in theory than in practice.

The term “mesclun” refers to a mix of baby greens. The traditional French mesclun mixes provide a blend of flavors, with lettuce serving as the mild backdrop for spicy arugula, piquant mustard and a bitter green like radicchio, endive or escarole. Gardeners often add weeds and leafy herbs, such as dandelion, purslane, orach, chervil, leaf celery, sorrel, chives, parsley and fennel.

The problem with mesclun mixes is that these plants have different temperature preferences and grow at different rates. If they’re lucky, gardeners will have one good harvest. After that, all too often, the chervil goes wild, the arugula starts to bolt, and escarole outcompetes the lettuce, or something along those lines.

Market gardeners often produce mesclun by growing several greens and mixing them together after harvest. By doing this, growers can maintain the same ratio of greens throughout the season. It is also easier to spot (and pick out) discolored leaves in single-variety rows.

Maximizing garden space

Spinach and leaf lettuce are great for planting with slow-growing crops. For example, the greens can fill up the space between onion seedlings early in the spring and then be harvested long before they start to compete with the onions.

I plant spinach and lettuce on the north side of pole beans and peas. In the spring when temperatures are cool, the greens get full sun. By the time the hot weather comes, the beans and peas are tall enough to shade the greens.

Garden pest control

Slugs can be a major problem with all greens. While there are many ways to counter-attack slugs — beer bait, copper wire, iron phosphate pellets, ducks around the garden, crushed eggshells around the base of plants — nothing is completely effective. I kept ducks in my garden to control slugs, but the ducks soon developed an appetite for my lettuce as well. Beer traps attracted skunks, which drank the beer — thereby liberating the slugs — and then dug up my potatoes. Picking slugs at night or early morning isn’t fun, but it does work.

Brassicas attract a legion of pests, including cabbage worms, cabbage root maggots, flea beetles, cutworms and slugs. Crop rotation will help reduce these pest problems. After you plant brassicas in one part of your garden, wait at least three years before planting them in the same bed or row.

A floating row cover is a useful tool when combined with crop rotation. If you tend to have problems with flea beetles, root maggots, leaf miners or cabbage worms, cover the soil immediately after planting.

Wood ash can also be used with caution to deter certain pests. Apply around the base of plants and/or in the hole before transplanting to reduce problems with slugs, cutworms and root maggots.

Companion planting can be used to minimize pest problems. Certain plants attract beneficial organisms that attack pests. For example, marigolds and nasturtiums provide great living conditions for lady beetles (ladybugs). Their larvae eat huge numbers of aphids and other small pests. Cosmos, wild mustard and Queen Anne’s lace offer food for parasitic wasps. These tiny wasps, which pose no threat to people, destroy cabbage worms and armyworms.

Other crops or even weeds can be good companions. Flowering wild mustard, parsley and cilantro attract parasitic wasps. Alternating rows of cabbage or Brussels sprouts with beans has been found to help lower damage from cabbage root flies, aphids and flea beetles.

Whatever you do, avoid planting a large area with one type of plant. That can draw pests like a magnet. Gardens and farms with a diversity of plants tend to have fewer pest problems than monocultures. Just another excuse to let your weeds grow and enjoy flowers in your vegetable patch.

How to harvest greens

Greens can be harvested by using scissors, a knife, an electric carving knife or an expensive greens cutting machine.

They should be cut early in the morning or on overcast days to avoid harvesting limp greens. This is particularly important for lettuce, which should be cooled immediately after harvest. Heat induces bitterness in lettuce, but the leaves will become sweeter after being stored in cold conditions.

Once you get hooked on greens, there is no end to your adventure. You can grow hundreds of types, try blanching bitter greens, or develop your own salad and braising mixes. The opportunities are endless, and hopefully the harvests last the entire growing season.


Broadcasting

Seed for mesclun and other baby greens is sometimes broadcast — scattered over a whole bed. This leads to efficient harvesting but a greater risk of mildew.

If you broadcast a seed mix, be sure you can identify the plants. The first time I planted arugula, I had never seen the plant. A few weeks later, while weeding wild mustard, which looks remarkably like arugula when young, I suddenly realized many “weeds” were growing in a line. I looked closely at the plants I had pulled and discovered that some (the mustard) were slightly hairier than the others (the arugula). Once I “weeded” all of the edible chrysanthemum in a mesclun mix. If you don’t know what all the plants look like, sow a row rather than broadcast.


To sow or to transplant

With all greens, you can start seedlings inside and transplant, or direct seed. Here are some considerations:

Direct seeding

Advantages

• Fast and simple

• Plants never undergo transplant shock so are less likely to bolt

Disadvantages

• Lower rates of germination and establishment than transplanting; this can lead to a waste of seed and garden space

• Seedlings are more vulnerable to pests and climatic stress

Transplanting

Advantages

• If you start transplants in late winter, you can get a jump on the season by planting them out as soon as the soil can be worked

• Transplants are often large enough to withstand pest pressure that might kill small seedlings

• Little or no seed is wasted

• Makes efficient use of garden space

• You can provide ideal conditions for the seedlings by controlling temperature, moisture and light inside the greenhouse (or house)

Disadvantages

• Takes extra time to maintain plants inside and to transplant

• Need space in a greenhouse or in a house under lights or by windows

• You have to wait for appropriate weather (calm, overcast or rainy) to transplant

• Transplant shock is common — this can either set back the growth of transplants or induce bolting. Make sure to harden off plants to get them acclimated to the outdoors

• Requires skill and delicate handling


Bolting: The bane of growing greens

Bolting occurs when a plant stops producing leaves and starts to form a flower stalk. The leaves usually become bitter and tough. Most greens bolt prematurely when stressed by warm weather, dry conditions or overcrowding. The key to growing great greens is to delay bolting for as long as possible by providing optimal growing conditions.


Janet Wallace is a freelance writer and organic gardener living on the shore of the Bay of Fundy in New Brunswick, Canada. The cool bay breezes provide the perfect conditions for growing greens from early spring to winter.