Their names are sometimes unfamiliar and their tastes exotic. Leafy greens are popular everywhere from gourmet restaurants, farmers' markets and supermarket produce sections to backyard gardens. The extensive variety of greens available today offers creamy or crisp textures, sweet or pungent flavors, and colors in beautiful shades of green and red. In some mild climates, greens can be grown year round for a harvest that lasts for months. Versatile and fast growing, greens can be harvested at almost any stage of growth and eaten raw or cooked. On the dinner table, greens are filled with flavor and nutrition for a culinary one-two punch.

History

Greens have been eaten for centuries. There is evidence that they were part of the diet of prehistoric hunter-gatherers who ate plants found growing in the wild. Asian greens such as mustards and mizuna have been cultivated for more than 2500 years.

Lettuce has been enjoyed since 550 BC when it was first served to Persian kings. These early types of lettuce were probably collected from the wild and looked different than the varieties eaten today. It is believed that the leaves grew on tall stems much like the stalks that form on our modern varieties when they bolt. The Assyrians and the Egyptians ate lettuce and thought that the milky sap found in lettuce plants was an aphrodisiac. Paintings of a lettuce with long pointed leaves similar to today's romaine varieties have been found in Egyptian tombs.

The Romans were especially fond of a type of lettuce with erect leaves that had been found growing on the island of Cos in Greece. Today it is known as romaine, named after the place where it was popular, or Cos, for its place of origin. It has been grown for thousands of years and may be the oldest lettuce variety still cultivated today. The Romans also liked arugula and ate it for good luck.

Corn salad, also called mache, was originally found in Europe growing in the fields of grain, commonly referred to as cornfields. Peasants working in the fields would collect the leaves to eat. It became popular when served to the elite during the reign of Louis XIV.

In the U.S. greens have been served on dinner tables since the early settlers arrived from Europe. General George Washington recommended that his soldiers eat them as "they are very conducive to health, and tend to prevent the scurvy." In 1777, Washington issued a General Order stating that a person be sent out every day to gather the greens growing around the camp and have them distributed among the soldiers. President Thomas Jefferson was an avid horticulturist who grew a variety of greens in his gardens including a selection of lettuces, along with endive, cress, spinach, corn salad and others. The English naturalist Richard Parkinson wrote in the late 1790's about the popularity of greens that "Indeed, in the spring they boil everything that is green, for use at the table."

Nomenclature

Greens are a diverse group of plants that are grown and eaten primarily for their edible leaves. Not always green in color, leafy greens can be red or purple, flecked, speckled or multicolored. Mesclun is a term given to mixes that contain a variety of leafy greens. (See the National Garden Bureau's Fact Sheet on Mesclun.) Greens can be harvested at many different stages of growth. As a "micro-green," plants are harvested as young seedlings with only one or two true leaves, usually within 10 to 14 days of planting the seeds. They are delicious in salads and sandwiches, and often used as an edible garnish. Allowing plants to grow a couple more weeks, they can be harvested for use as "baby greens." Small but full of flavor, the tender, bite-sized leaves are an essential element of gourmet menus. Of course, greens can be allowed to grow to full size before being harvested.

Classification and Varieties

Many of the greens grown today are Brassicas from the Brassicaceae (also called Cruciferae) or cabbage family. This family of economically important plants includes broccoli, cabbage and cauliflower and gives us a wide variety of greens including arugula, mizuna, tatsoi, cress, collards and mustard greens. Most greens are annuals, though sorrel and cress are perennials that can be grown as annuals.

• Arugula (Eruca sativa) also called roquette, rocket salad or rocket, is easy to grow with green leaves that are lobed and add a spicy snap to salads. A popular green in Europe, it is used in many Italian and French dishes. When young, the leaves have a mild, radish-type zip that is sometimes compared to the flavor of horseradish. Many people like to combine arugula with other milder greens to balance the stronger flavor. Arugula is ready to harvest in 4 to 6 weeks.
• Asian greens such as mizuna (Brassica rapa japonica) and tatsoi (Brassica rapa rosularis) are making a splash in American gourmet cuisine. Mizuna has white stems and delicate green leaves with finely cut fringed edges. Fast growing and delicious, mizuna is ready to eat in 20 to 40 days. It is tolerant of most weather even growing in hot temperatures without bolting. Tatsoi, also called spoon cabbage or rosette pak choi, has very dark green leaves, appearing almost black in color, with a mild peppery flavor. Tatsoi is very weather tolerant and continues to grow through cold temperatures and light snow. It also tolerates heat so you can make several plantings from spring through fall. Tatsoi is delicious as a baby green and it grows quickly into mature plants that are ready to harvest in 5 to 7 weeks.
• Cress, also called garden cress or pepper grass (Lepidium sativum) is a fast growing green harvested as a sprout within a week or so after germination. It has a tangy, pepper-like flavor and aroma. 'Wrinkled Crinkled Crumpled' cress is aptly named. It is a fast growing, large leafed cress with extremely curly leaves that takes a little longer to mature and is ready in about 14 to 21 days. Garden cress is different from watercress (Nasturtium officinale), a perennial that grows in running water or very damp areas. However, 'Presto' is a popular cress variety with a flavor similar to watercress. Land cress (Barbarea verna) is a related perennial cress that is known by many different names including American cress, early wintercress, early yellowrocket and in the South, creasy greens. Unlike garden cress, it is eaten about 7 weeks after sowing when plants have developed 6-inch diameter rosettes of glossy, dark green leaves. It is similar to watercress but is easier to grow in the garden.
• Collards (Brassica oleracea, Acephala group) are a type of non-heading cabbage with large, blue-green, coarse leaves with a distinct cabbage-like flavor. Each plant produces many leaves and can be harvested as a micro-green, baby green, or when fully mature. Collards grow well in the heat making them a favorite of Southern gardeners, yet they're extremely hardy and tolerate temperatures down to 15 degrees Fahrenheit so even Northern gardeners will get a harvest. Exposure to frosts sweetens the flavor of the leaves. 'Georgia' is a popular variety in the South because of its heat tolerance. Plants mature in 70 to 80 days and reach 24 to 30 inches tall. 'Vates' is a low-growing, compact variety with thick, broad leaves that mature in 75 days and also overwinters well. 'Champion,' a selection of Vates, is even more compact with the same rich, dark green leaves, yet ready to harvest two weeks earlier.
• Mustard greens (Brassica juncea) are a cool-season vegetable that produces large leaves that get a foot or more tall. They withstand some frost but may bolt when day lengths get longer in the spring. You can begin harvesting the outer leaves from mustards when they are only 3 to 4 inches tall. 'Southern Giant Curled' is a longtime favorite and a 1935 Gold Medal All-America Selections winner. Slow to bolt, the upright bright green leaves have curly edges. It can be harvested in 35 to 50 days. If you want color, choose the beautiful 'Red Giant.' True to its name, the large leaves are up to 18 inches tall with a beautiful reddish bronze color and reddish purple veins. It's ready to harvest for baby greens in about 3 weeks and reaches full size in 35 to 45 days. The leaves have the tangy flavor of gourmet mustard. 'Ruby Streaks' is stunning and delicious. The attractive and sweet leaves are finely serrated when young, then look more like mizuna when mature. Leaf color varies from dark green with red veins to dark maroon. It is ready to harvest in 3 to 6 weeks and makes a beautiful addition to containers, flower borders or the vegetable garden.
• Lettuce (Lactuca sativa) is from the Asteraceae or daisy family and is the foundation of any vegetable garden. Easy to grow and quick to harvest, there are hundreds of varieties available to gardeners. The leafy or non-heading types of lettuce are most often used as greens. This includes varieties of bibb, romaine, leaf and Batavian lettuces.

  Bibb lettuce has a whorl of open/semi-open leaves with a very dense, almost romaine-like heart.

  Butterhead or Boston lettuce forms a semi dense ball. The leaves are less crisp than bibbs and have a wonderful buttery texture. They reach full size about 8 to 10 weeks after planting. 'Buttercrunch' is a long-time favorite and 1963 All-America Selections winner. The compact heads produce delicious, green leaves that can be harvested when small and served as an individual-sized salad. Even smaller is 'Tom Thumb,' a crisp and sweet butterhead about the size of a tennis ball. This is an ideal variety for growing in containers or for gardeners with very limited space. The French heirloom 'Marveille de Quatre Saisons' lettuce is one of the earliest to harvest and has outer leaves of reddish brown with cranberry red edges and a creamy yellow center.

  Cos or romaine lettuce has large green wrinkled leaves with a nice crisp texture and flavor. The oblong leaves grow upright and form loose, cone-shaped heads. It is the essential ingredient for a traditional Caesar salad. Romaines take a little longer to reach full size than other types of lettuces, generally 9 to 10 weeks after planting, but they are also more heat tolerant. 'Parris Island Cos' is a standard romaine with crinkled, medium green leaves that form a large tight head. It resists tip burn and is slow to bolt. 'Little Gem' is an heirloom variety with tight green leaves that are sweet and crunchy. These small plants are delicious when cut at 5 to 7 inches tall. 'Rouge d'Hiver' or Red Winter is another heirloom popular for the nicely sized heads of reddish-bronze leaves that stay crisp after harvest. It is very tolerant of both hot and cold temperatures making it ideal for any garden.

  Leaf lettuce provides a quick harvest and comes in a variety of colors, shapes and textures. Seed racks and catalogs are filled with so many varieties it may be hard to choose which one to grow. Fortunately a lot of lettuce can be produced from a small row or even in a container so there's probably room to plant more than one variety. Or choose one of the many custom lettuce blends created by seed companies. These mixes are a great way to sample many different lettuces from a single packet.

  Lettuces are very easy to grow and produce vigorously until summer's heat. Leaves come in shades of green and red ranging from light lime green to deep wine red. They can be harvested at almost any size but most reach full size 40 to 50 days after planting. Leaf lettuces are also popular as cut-and-come-again lettuces. When the leaves are mature, harvest the whole plant, just make sure to cut above the growing point so that the plant will grow back to provide a second harvest of tasty leaves.

  'Black Seeded Simpson' continues to be one of the most popular leaf lettuces prized for its large, light green crinkled leaves and its tolerance of drought, heat and frost. It is also slow to bolt so leaves can be picked over a long harvest period. 'Red Sails' is a 1985 All-America Selections winner that has soft, buttery leaves ruffled and edged with burgundy. The darkest of lettuces, 'Merlot' forms loose heads of sweet red leaves that appear almost purple. 'Speckles' is a European heirloom with green leaves spattered with red to add lovely color to any salad or mix of greens. For fullness and texture, add the frilly-leaved 'Lolla (or Lollo) Rossa' with green leaves edged with red. All of these leaf lettuces make an attractive edible ornamental for edging borders and filling containers. The foliage can even be used to add color and texture to the flower garden.

  Summercrisp lettuce, also known as Batavian lettuce, is not as common in American gardens as other types of lettuce. However, they make wonderful greens with a nice crisp texture and sweet flavor. Plants are like leaf lettuce when young but as they mature, they begin to form larger heads that are ready to harvest in 50 to 60 days. They have superior heat tolerance and are commonly grown in places with relatively warm weather such as the South of France. 'Nevada' has thick, bright lime green leaves that form heavy, upright heads like a loose romaine. Plants have good disease resistance and grow well in all climates. 'Rouge Grenoblois' is a bicolored Batavian in green and crimson.

• Mache or corn salad (Valerianella locusta) is also called lamb's lettuce. Mache is from the Valerianaceae family, which includes garden perennials - Jupiter's beard and valerian. Mache's glossy, spoon-shaped leaves are mild with a sweet nutty flavor and grow in attractive small rosettes. 'Vit' is a popular variety that can be grown in both spring and fall, and produces a dense mound of firm, leaves with tender flavor. With good cold tolerance, it is also ideal for overwintering when grown in milder climates. Large-Seeded Mache is best grown in spring because it can handle higher temperatures before bolting. Mache reaches full size in about 7 weeks.
• Garden Sorrel (Rumex acetosa), sometimes called spinach dock, is a member of the buckwheat family, Polygonaceae. It is a hardy perennial in USDA zones 4 to 9, but often grown as an annual. As a perennial, it is one of the earliest greens to harvest in the spring. It continues to produce into fall and often early winter, withstanding temperatures well below freezing. The long green spoon-shaped leaves have a sharp, mildly sour, lemony flavor. 'Red Veined Sorrel' has contrasting dark red stems and veins for added color. Harvest of small leaves can begin at any time, while leaves are fully mature in 55 to 60 days.

How to Grow Greens

Starting from Seed

Greens are generally started from seed and are readily available in packets from retail stores, catalogs and Internet seed companies. Economical and easy to start from seed, they are available as individual varieties and in pre-made seed mixes in a range of flavors, colors and uses to suit any gardener or cook.

Greens grow best in a fertile, well-drained soil. Add compost or well-rotted manure to the soil before planting to improve drainage and add nutrients. Scatter seeds in a row and cover lightly with soil. Keep moist until seeds germinate, usually within 7 to 14 days. After seeds germinate and start growing, start to thin crowded seedlings. The best way to remove excess plants without damaging the other seedlings is to pinch them at the base of the stem with your fingernails or snip them off with a sharp scissors. But don't throw these seedlings away. The small thinnings are delicious in salads and sandwiches.

Most greens like to grow in full sun, but they will produce in areas with light shade. Sow seeds outdoors in spring or fall. For an extended harvest, make smaller plantings every two weeks. As summer approaches, plant varieties of greens that are heat tolerant or resist bolting. Additional plantings of greens can be made in late summer or fall (up to a month before the first frost) for harvest during the cooler temperatures. In mild climates, greens can be planted throughout the fall and winter. Greens can also be grown in an unheated greenhouse, under row covers and in cold frames to extend the growing season.

Starting from Transplants

Because of their popularity, lettuce, mustards and other greens can be found in garden centers in containers or six-packs for transplanting. To ensure a successful crop, be sure to prepare garden soil.

Growing in Containers

Greens are ideal for growing in pots and containers. Choose a well-drained container that's at least 4 to 6 inches deep and fill with a soilless media available at retail stores. Check the soil daily to make sure it hasn't dried out and water as needed. Containers may need to be watered a couple times a day when temperatures begin to warm. If growing micro-greens, seeds can be planted in shallow flats and harvested about 10 to 21 days after planting. If given adequate light, they can also be grown indoors during the winter.

Pests and Diseases

Greens are relatively free of pests and diseases because they grow quickly, often in cooler weather when fewer insect pests are present. However, it's a good idea to check plants regularly to prevent a minor problem from turning into a major garden disaster.

Since leaves are eaten, do not use any chemical pesticides. Remove insects by hand picking or washing them off plants with a stream of water from a garden hose. Another way to control insect pests is to encourage ladybugs, lacewings and other beneficial insects in your garden. These "good bugs" are natural predators of aphids, mites and many other damaging insects. Beneficial insects are sold in many garden centers and online stores.

Growing greens in a well-drained, fertile soil, with good spacing between plants will prevent most common disease problems.

Harvesting and Storing Greens

Greens are versatile and can be harvested at almost any stage of growth. For micro-greens, harvest seedlings when they have one or two true leaves, usually 10 to 21 days after being planted. To use as baby greens, pick leaves after 3 or 4 weeks of growth. Entire plants can be harvested or remove leaves at the base of the plant starting with the outer leaves. Inner leaves will continue to grow and new leaves will be produced from the center.

Adequate spacing is most important when growing plants to full size. This is easy to accomplish by simply thinning plants as they begin to get crowded in the garden. Mature greens need about 8 to 10 inches between plants. When plants reach full size, harvest the entire plant by pulling the plant out of the ground or cutting it off at the soil line with a knife or sharp scissors. Plants that have reached the end of their growing cycle will send out a flower stalk, a process called bolting. Many greens will also bolt when temperatures get too high. When this happens, leaves become bitter tasting and inedible, so remove the plant or plants and place in the compost bin.

Greens are best eaten fresh from the garden but can be stored in a vegetable crisper in the refrigerator for a day or two. Lettuce, collards and mustard greens can be kept longer, from 3 days to a week. Before storing, remove any remaining soil and damaged or discolored leaves that you won't be eating. Place in a plastic bag. Clean greens thoroughly by rinsing with cold water just before using.

Using Greens in the Kitchen

These versatile plants can be eaten raw or cooked in a variety of recipes. Greens are low in calories yet loaded with nutritious vitamins and minerals. Fresh greens are ideal for eating in salads and on sandwiches. Create wilted greens by adding a warm salad dressing to a plate of fresh greens just before serving. Greens can be added to soups, casseroles, even used as pizza topping. Because greens contain a lot of water, they are generally added right at the end of the cooking time or cooked quickly to avoid turning to mush.

Asian greens, collards and mustard greens are often sautéed, steamed, braised or added to stir-fry dishes. Collards or mustard greens simmered until tender with salt pork is a favorite Southern dish. Sorrel soup is a traditional spring soup served in Russia and Eastern Europe, while the lemony flavor of the leaves tastes great in a sauce paired with fish.

Whether it's the enjoyment of growing healthy plants or the pleasure of delicious food, gardeners and cooks alike appreciate the versatility of greens. This is the year to fill your garden and your kitchen with the inspirational colors, flavors and textures of leafy greens.

For More Information

The National Garden Bureau recognizes Janis Kieft as the author of this fact sheet. We wish to thank the experts who reviewed our text. Steve Bellavia of Johnny's Selected Seeds, Stephanie Turner of Geo. W. Park Seed Co. Inc., and Susan Jellinek of Thompson & Morgan greatly assisted in our efforts to provide accurate information.

The 'Year of the Mesclun' fact sheet is a service provided by the National Garden Bureau. The National Garden Bureau is a nonprofit organization and recognizes the seed company members who donate the money to publish these materials.