Shorter days and cooler temperatures tell us that summer is about to end. But this doesn’t mean it’s time to wrap up gardening for the year. Leafy greens are an easy and delicious way to squeeze a few more weeks of productivity from your garden. With a little extra effort, it’s possible to grow fresh produce all winter.
This article begins with short descriptions of leafy greens that grow well in Virginia. It then discusses how to get leafy greens started in your garden as summer wanes (or as spring begins) and optimize production through autumn, winter, and into next summer.
Types of Leafy Greens
Lettuce (Lactuca sativa): Most home gardeners, including me, find growing leaf lettuce easier than head lettuce (e.g. iceberg). Leaf lettuce comes in a variety of colors, textures, and flavors. Seed mixtures are an economical way to grow a diverse set of lettuces for tossed salads. Some varieties are heat-resistant, which is essential for spring planting.
Kale and collard greens (Brassica oleracea var. acephela): These greens are related to cabbage, but as the name suggests, don’t form heads. How do kale and collards differ? Kale leaves are thinner and softer. In other words, they can be eaten raw. Collards are thicker and almost always cooked before consumption. There are more kale varieties (red Russian, Lacinato/dinosaur/Italian, curly green and red) than collards, which usually have flat, green leaves. All are delicious!
Swiss chard (Beta vulgaris): Chard is a member of the beet family (beet greens are also delicious). Varieties differ in the color of stems and ribs, from white to yellow to pink to red, but generally taste the same. Chard is highly resistant to bolting in warm weather and can tolerate cold temperatures. In other words, chard planted now can over-winter and will produce through next spring and summer.
Spinach (Spinacia oleracea): Spinach is versatile: it can be harvested early or late, and it’s delicious raw or cooked. “Savoy” spinach has thicker leaves with a ruffled surface and a stronger flavor than other varieties. Spinach germinates poorly at high temperatures (above 75°F), so unless you’re planning to transplant, it’s better for spring planting.
Broccoli raab, aka rapini (Brassica rapa var. ruvo, or Brassica ruvo): This relative of turnips (you guessed it, turnip greens are tasty too) is common in Italian cuisine. Raab is leafier than “standard” broccoli, and the stalks are good to eat. The strong, spicy flavor of raab is slightly bitter and a tad sweet. Unless harvested young, it’s best when cooked.
Mustard greens (Brassica juncea): This leafy green also has strong, spicy flavor. Typically, it’s cooked, although young, raw mustard greens are a great addition to tossed salads. Mustard greens are quite susceptible to bolting in warm weather.
Asian greens: This is a broad category! Asian greens warrant a separate article, which Piedmont Master Gardener Pat Chadwick has recently written. Suffice it to say, these greens grow well in Virginia and are a fantastic addition to any diet. Some well-known examples are mizuna and tatsoi, which have a mustardy, peppery flavor. They are terrific both cooked and raw in green salads. Another variety, gai lan, is similar to broccoli raab. Most seed catalogs offer Asian greens, and transplants are easy to find at local garden centers.
Growing Leafy Greens
Soil preparation: Prepare the soil before starting your greens. A soil test will tell you if any amendments are needed. Soil pH should be 6 – 7, slightly acidic to neutral. Leafy greens thrive in loamy soil, which can retain moisture without becoming waterlogged. It might be necessary to add compost to clay soil to improve its texture and drainage. A good rule of thumb for clay soil is to incorporate 4 inches of compost into the top 12 inches of soil. That’s a lot of compost – and a lot of work – but it will be worth the effort. Regardless of any amendments, thoroughly rake the top 2 inches of soil to break up any clumps.
Getting Started: Leafy greens can be started by transplant or direct sowing into a garden bed. The choice depends on the season and type of greens. For example, spinach seeds germinate poorly at temperatures above 75°F, so transplanting makes more sense for late summer planting.
For direct sowing, follow the directions on the seed packet for depth, spacing, and timing. Cover seeds with soil, then water thoroughly for good contact between soil and seed. Thin seedlings after a couple of weeks if desired. Trimmed seedlings make an excellent baby green salad.
Transplanting can be done with plants from a garden center or farmers market, or with seedlings you’ve started yourself. Start seeds on the same timetable as direct seeding, and harden off seedlings before transplanting. Piedmont Master Gardener Liz Sutphen has written a comprehensive guide to starting seeds indoors.
Cultivation: Leafy greens are vigorous and don’t need much coddling. Irrigate and fertilize appropriately. Weed thoroughly but carefully because most leafy greens have shallow roots. Mulch (leaves or grass clippings) can suppress weeds and help soil retain moisture.
Disease and pests: Leafy greens suffer from some fungal diseases, including root rots, downy mildew, and leaf spots. Prevention is easier than cure. Rotate crops to keep soil-borne pathogens from accumulating. To prevent root rot, do not over-water. Amend clay soil to improve drainage. Water in the morning to keep leaves dry. Direct water towards the base of the plants, but don’t splash dirt onto the leaves. Practice good sanitation: remove plant debris during and at the end of the growing season. This will deny a habitat to pathogens and insects.
Fungicides can be a helpful preventive. Products containing copper or chlorothalonil are useful against fungal diseases. Consult the Virginia Cooperative Extension Pest Management Guide for more details. Always follow instructions on the product label (“the label is the law”) and wait the indicated number of days between application and harvest.
Pests such as aphids, whiteflies, “worms” (actually, caterpillars), harlequin beetles, leaf miners, and slugs are a more serious threat to leafy greens. Again, prevention is easier than cure. Rotate crops to keep plants away from eggs and larvae in the soil. Sanitation (cleaning up plant debris) will deny insects a place to hide in the first place. Some growers use lightweight row covers to keep insects away from leafy greens. Bt (Bacillus thuringiensis) can help keep caterpillars away. Diatomaceous earth spread on the ground around your greens can control slugs and soil-dwelling insects.
If insects emerge, hand-pick caterpillars and large beetles off plants. Neem oil is effective against aphids and whiteflies. Control severe infestations with conventional insecticides, including malathion and carbaryl. Consult the Virginia Cooperative Extension Pest Management Guide for more details. Always follow label instructions carefully: “the label is the law.” To minimize harm to pollinators, don’t spray flowering plants, and spray in the evening when pollinators are less active. This advice also holds for organic treatments like pyrethrins and diatomaceous earth, both of which are extremely harmful to honeybees. Use all insecticides with caution since they can kill beneficial predatory insects and pollinators.
Harvest: Use the “cut-and-come-again” harvest method for non-heading greens. Trim the outer leaves of the plant, avoiding the central area where new growth occurs. This practice will allow plants to produce for weeks, if not months, though the plants may look a little funny after a while (see picture).
Over-wintering: Practically every leafy green is cold-hardy and can handle a light frost with no trouble. In fact, flavor usually improves after a touch of frost because the plants respond by producing more sugars for cryo-protection. With help from row covers, leafy greens can easily survive a Virginia winter. Piedmont Master Gardener Ralph Morini’s article on season extension using row covers will tell you everything you need to know. Four-Season Harvest by Eliot Coleman is another excellent introduction to this topic.
Over-wintered greens will resume growth in the spring. In my experience, over-wintered kale bolts surprisingly early in the spring, but settles down to “vegetative” growth after I cut back the flowering stems. Bolted raab, on the other hand, doesn’t return to leafy growth after trimming, so I harvest it all in the spring. As mentioned above, chard is the champion of heat and bolt resistance, and can be reliably productive for a full calendar year.
Preparing Leafy Greens
Simplicity is my personal preference for preparing leafy greens. “Baby” greens can be eaten raw in a tossed salad. Both mixed greens and salads with a single type of green are excellent. Blanching, sautéing, and stir frying are all great ways to prepare mature greens. Blanched greens can be drained and frozen. Or, boost color, flavor, and nutrition by throwing a handful of sliced greens into simmering soup a couple minutes before serving. The soup doesn’t have to be homemade. Of course, thicker greens like collards can be steamed until tender, then served with vinegar or hot sauce on New Year’s Day.
PESTICIDE WARNING
Pesticides (which include herbicides, insecticides, rotenticides, etc.) are poisonous. Always read and carefully follow all precautions and safety recommendations given on the container label. Store all chemicals in the original labeled containers in a locked cabinet or shed, away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock. Consult the pesticide label to determine active ingredients, signal words, and proper protective equipment.Pesticides applied in your home and landscape can move and contaminate creeks, lakes, and rivers. Confine chemicals to the property being treated and never allow them to get into drains or creeks. Avoid drift onto neighboring properties and untargeted areas.
References and Further Reading
Featured photo credit: Sterling College, CC BY 2.0
2022 Pest Management Guide – Home Grounds and Animals Virginia Cooperative Extension
Asian Greens University of California Master Gardener Program of Sonoma County
Asian Vegetables for Virginia Gardens Pat Chadwick, Piedmont Master Gardener
Brassica oleracea (Acephala Group) North Carolina Extension Gardener Plant Toolbox
Crop Profile for Broccoli Raab (PDF link) University of Arizona
How to Control Invasive Pests While Protecting Pollinators and Other Beneficial Insects Michigan State University
How to Grow Swiss Chard Michigan State University Extension
How to Start Your Garden Seeds Liz Sutphen, Piedmont Master Gardener
Leafy Green Vegetables Virginia Cooperative Extension
Mustard University of Illinois Extension
Row Covers Utah State University
Row Covers – A Gardening Season-Extender with Benefits Ralph Morini, Piedmont Master Gardener
Spinach Clemson Cooperative Extension
Spinach Penn State University Plant Village
Virginia’s Home Garden Vegetable Planting Guide: Recommended Planting Dates and Amounts to Plant Virginia Cooperative Extension
