Millennia ago, a kale-like, loose-leafed wild plant, native to the Mediterranean, was domesticated and became a cabbage-like vegetable. This was later developed into our modern brassica vegetables, which include cabbages.
The brassicas that belong to Brassica oleracea include the classic cool-season vegetables broccoli, brussels sprouts, cabbage, cauliflower, kale, and kohlrabi. These are very hardy vegetable crops that are best grown in areas with a cool winter—in fact it is believed that frosts will actually improve the flavor of some brussels sprouts and kales. Some varieties have more heat tolerance. The Asian greens brassicas, classified as B. rapa and B. juncea (see here) tend to be more tolerant of tropical or subtropical climates. Supermarkets may have cool-season brassicas for sale all year round, but it is during winter and spring that the home gardener can enjoy them at their flavorsome best.
Millennia ago, a kale-like, loose-leafed wild plant, native to the Mediterranean, was domesticated and became a cabbage-like vegetable. This was later developed into our modern brassica vegetables, which include cabbages.
Brassicas like a fertile, well-prepared soil that is well drained, high in organic matter, and slightly alkaline. Grow them from seeds or seedlings in late summer and autumn, with repeat plantings into winter.
Problems The main problems for these plants are snails and slugs, which hide within their foliage; the caterpillars of the cabbage moth and cabbage white butterfly, which eat the leaves; and gray cabbage aphids, which hide in the heart of young seedlings. All are less likely to affect strong, healthy plants. Some soil-borne diseases can also affect these plants, but good crop rotation practices should eliminate them.
Caterpillars are more active in the warm weather of autumn and spring. You could pick off and destroy them or spray them with a biopesticide—always observe the withholding period before you harvest any produce—but exclusion is best. Net plants with floating row covers or cover them with movable frames of fine wire mesh. You can also distract butterflies from laying eggs on your produce by leaving half eggshells around. The butterflies lay their eggs on these instead—gather them up weekly, crush, and add to the compost. The usual insect predators of aphids are less active in low temperatures, when cabbage aphids are present. Squash them or spray off with a strong hose, or you may need to use a biopesticide.
Broccoli and cauliflower should have clean, bright, tightly closed heads (broccoli may have a purplish tinge to the green). Cabbages and brussels sprouts should be tightly closed, with bright, unblemished leaves. Kale should have firm leaves with no sign of wilting or yellowing. Choose small kohlrabi, which will have better flavor than large ones, with unblemished skin. Store in loosely sealed plastic bags in the crisper section of the refrigerator for up to a week, or blanch and freeze for future use.
Applying cooked or raw cabbage leaves externally is a traditional remedy for breast engorgement in nursing mothers and for the pain of varicose veins and arthritis. When eaten, cabbage and other brassicas offer a wealth of protective compounds. These include glucoraphanin, gluconasturtiin, and glucobrassicin in broccoli and brussels sprouts and sinigrin in cabbage. These compounds have been shown to support the body’s natural detox system and block enzymes that increase the risk of DNA damage, which can lead to cancer. The fiber in brassicas may help control cholesterol, too.
Brassicas are also sometimes called cruciferous vegetables after the shape of their tiny, four-petaled, cross-like flowers.
Brassica oleracea Botrytis Group, Italica Group
Broccoli produces rounded green heads of unopened flower buds. It is usually lightly steamed or stir-fried, but it has a delicious taste when picked fresh and eaten straight from the vegetable garden.
New types of broccoli are released every year, and all taste great. Pictured here (clockwise from top left) are the familiar single-headed broccoli, the individual florets of broccoli sold as broccolini and purple sprouting broccoli.
Plant seedlings 40–50 cm (16–20 in) apart, allowing space for the heads to mature. For continuous supply, plant a few seedlings every four to six weeks until the end of winter, if space allows.
Harvesting The heads take from two to three months to develop and should be cut as required when they are firm and tight and before they start to flower, usually when they are around 10–15 cm (4–6 in) across. Once you cut the central head, the plant produces smaller side shoots and can keep producing for another four months.
While most people are familiar with single-headed broccoli, with heads up to 20 cm (8 in) across, for home gardeners there are other varieties to choose from. These include sprouting broccoli, which produces many smaller heads of Broccolini-like shoots, and broccoli raab, or rapini, the traditional Italian vegetable whose leaves, stems and small, button-size heads have a more intense flavor. There are also purple varieties of both single-headed and sprouting broccoli, which not only look and taste good, but also are the original color of this winter vegetable. Another interesting variety is Romanesco, which produces lime-green heads of spiraled florets, themselves arranged in a spiral pattern.
Brassica oleracea Gemmifera Group
These swollen leaf buds that form on the sides of a central stem look like mini cabbages and have a unique flavor, which is at its best when the vegetable is homegrown. There is a purple variety, Rubine, as well as typical green varieties. The outer leaves can also be used as a leaf vegetable, like cabbage.
Space seedlings 60 cm (2 ft) apart to give the plants space to develop. They can reach 75 cm (2 1/2 ft) high and, given their height, can be damaged by strong winds. Either hill the soil up around the base of the plant as it develops or stake the thick plant stem. Remove the leaves from the bottom up as the sprouts start to form on the stem. Brussels sprouts are ideally planted in summer so they mature when the coldest—preferably frosty—weather occurs, although local conditions will determine planting times.
Harvesting Sprouts start to appear on the stem of the plant three months after planting and will continue to appear for several months. They start to mature from the bottom to the top, so pick the lower sprouts first. You can encourage sprouts at the top of the plant to swell by removing the cabbage-like head. Small sprouts have the best flavor, so harvest when they are tightly closed, immature and less than 2.5 cm (1 in) across.
Pan-fried brussels sprouts leaves with anchovies and garlic
Steamed, boiled, roasted, or pan-fried: no matter how you cook brussels sprouts, don’t overcook them. Done correctly, they have a wonderful taste with a nutty overtone. Here, anchovies, garlic, and red pepper flakes add flair and flavor to this underappreciated vegetable.
Peel the leaves off 750 g (1 1/2 lb) brussels sprouts and blanch in a large saucepan of boiling salted water for 30 seconds. Drain, refresh in cold water, and set aside.
Heat 2 tablespoons olive oil in a large nonstick frying pan over medium heat. Add 2 cloves thinly sliced garlic and 4 finely chopped anchovy fillets and cook, stirring, for 1 minute, or until the garlic is golden. Add the brussels sprouts and 1/2 teaspoon dried red pepper flakes and cook, tossing carefully, for 2–3 minutes, or until golden. Add 1 tablespoon lemon juice and season with freshly ground black pepper. Put in a large bowl and drizzle with extra olive oil to serve. Serves 4 as a side dish
There is no benefit in cutting a cross shape in the base of each brussels sprout. It does not reduce the cooking time, nor does it help to cook the sprouts more evenly. Instead, it is likely to make them soggy. One hypothesis is that the practice originated as a spell to “keep the devil out.”
Brassica oleracea Capitata Group
Cabbages are the classic brassica, with a wonderful, densely packed, rounded head that can weigh 1–6 kilograms (2–13 pounds). Once the head is harvested, secondary heads are unlikely, so you can pull the plant out. Cabbage is finely shredded and eaten raw in coleslaw or cooked as a vegetable.
Cabbages come in many shapes, including round, conical, and oval, and in many colors, including green and reddish purple.
Plant seedlings 40–60 cm (16–24 in) apart, depending on the variety, to allow space for the cabbage heads, or hearts, to grow. The heads of small varieties start to mature after 8 weeks, while large types take 14 to 22 weeks. For a continuous supply, plant seedlings every 4 weeks.
Harvesting Harvest when heads are firm and fleshy. Cut them off at the base with a sharp knife.
Small or miniature cabbages, such as Sugarloaf, are a good choice in limited space. For ornamental value as well as good eating, choose one of the reddish-purple varieties, such as Red Drumhead, or try one of the savoy cabbages with their characteristically deeply crinkled leaves.
Territorial pests
The cabbage white butterfly and cabbage moth are territorial, and you can use this to your advantage to protect your crops. Cut out butterfly shapes from white plastic containers, such as empty yogurt or ice cream cartons, and nail these to low garden stakes. Insert these around your brassicas and the real butterflies will be less likely to visit your young plants. Threading small chunks of white Styrofoam on fishing line, each about 30 cm (1 ft) apart, and stringing this around your brassicas will have the same effect. The cabbage white butterflies and cabbage moths will see these adornments as other butterflies and moths that have already claimed that particular territory, and so they will leave your brassica patch alone.
Sauerkraut with apple and bacon
Cabbage, sauerkraut’s star ingredient, has a reputation as a digestive aid. This traditional Eastern European recipe uses canned sauerkraut for convenience.
Discard the first layer of cabbage leaves from a 1 kg (2 lb) cabbage and cut in half. Remove and discard the core section and any thick ribs. Shred the cabbage and put in a large heavy-bottomed saucepan with 1 tablespoon olive oil and 2–3 slices diced bacon. Add 1 teaspoon salt, 6 peppercorns, and 2 bay leaves. Cover and cook over low heat for 1 hour, until softened, stirring occasionally.
Drain a 425-g (15-oz) can of sauerkraut, then add to the pan with 2 peeled and finely diced green apples. Stir to combine.
Cover and cook, stirring frequently, for a further 30 minutes, until the apples are tender and the sauerkraut is very soft. Add 3 tablespoons soft brown sugar just before the end of cooking and stir to combine the flavors.
Serves 6–8 as a side dish
Brassica oleracea Botrytis Group
No longer is cauliflower only available as a creamy white head. Now there are purple, orange and pale green varieties—the latter is sometimes referred to as broccoflower—all of which add visual interest to the vegetable patch. Like broccoli, cauliflower is mostly eaten cooked, but it also tastes delicious picked and eaten fresh from the garden.
Where garden space is limited, grow a few heads of creamy white, green, or purple cauliflower in the flower border.
Plant seedlings 50–60 cm (1 1/2–2 ft) apart to allow space for the heads to mature. Heads take three to five months to mature, and the part you eat is the unopened flower head. Unlike broccoli, it does not resprout successfully after harvest, so once you pick a head, the plant needs to be removed. To obtain a continuous supply, plant seedlings every two to four weeks if space and time allow, or choose several varieties that take different times to mature.
Harvesting Start harvesting heads while they are tight and firm and before the flowers open, ideally when heads are around 20 cm (8 in) across.
Cauliflower and cheese sauce are a perfect match, but you can bring excitement to cauliflower’s delicate flavor by adding spices or by roasting the florets.
Crispy spiced cauliflower
The coating on the cauliflower should be light, not a thick shell. Make sure you cut the florets into evenly sized pieces, not too large but not too small. They should be just tender when cooked.
Preparation: 20 minutes / Cooking: 1 1/2 minutes per batch / Serves: 6 as an appetizer or side dish
1 tablespoon cumin seeds
2 teaspoons coriander seeds
1/2 teaspoon ground paprika
1/2 teaspoon salt
1/3 cup (50 g) all-purpose flour
1 egg
1 egg white
1/2 cup (30 g) Japanese bread crumbs (panko)
1/2 cup (55 g) almond flour
1 cauliflower (about 1 kg/2 lb)
Vegetable oil for deep-frying
Aioli to serve
Heat a small frying pan over medium heat. Add the cumin seeds and coriander seeds and toast, stirring continuously, for about 30 seconds, or until fragrant. Transfer to a spice grinder or mortar and pestle, add the paprika and salt, and grind to a powder.
Put the flour in a plastic bag. Whisk the egg and egg whites together in a wide shallow bowl. Combine the bread crumbs and almond flour in another plastic bag.
Cut the cauliflower into florets and put in the bag with the flour. Hold the bag closed with one hand and shake to coat the cauliflower. Remove and shake off any excess. Add the cauliflower to the egg mixture and turn with your hands to coat—you don’t need perfectly even coverage. Transfer to the bag with bread crumbs and shake to coat.
Half fill a large saucepan or deep fryer with oil and heat over medium-high heat. Cook a few florets at a time for about 1 1/2 minutes, or until lightly golden—don’t overcrowd the oil or the temperature will drop and the cauliflower will be oily. Lift out with a slotted spoon, drain, and transfer to a baking sheet lined with paper towels. Keep in a single layer.
When all the cauliflower is cooked, sprinkle with the spices and toss to coat. Season with a little more salt, if desired, and serve with the aioli.
Note: There may be some larger pieces of coriander left after grinding the seeds, so sift the ground spices to remove them.
Cauliflower for the king
Louis XIV, who ruled France from 1643 to 1715, built the palace at Versailles as a symbol of his wealth and absolute power. The Sun King showed a fondness for the humble cauliflower, or chou-fleur, a vegetable not highly regarded at the time. The king liked it cooked in stock, seasoned with nutmeg, and served with butter.
Brassica oleracea Acephala Group
Also known as borecole
This easy-to-grow vegetable is often described by nutritionists and food lovers as a superfood due to the high levels of iron and antioxidants in the leaves. There are several varieties of this nonhearting cabbage, including some grown for purely ornamental purposes. The popular culinary types have ornamental as well as culinary appeal—the best-tasting leaves are harvested in winter. Kale can be eaten raw, straight from the plant, blended in a green smoothie, or lightly steamed, sautéed with garlic, or added to soups and stews.
The striking purple and white ornamental kales are popular as bedding plants. A spectacular addition to any garden design, especially a massed planting, they are not for eating.
Lacinato kale, or Tuscan kale, is a very popular variety for cooking. It is used traditionally in minestrone, a mixed vegetable soup of Italian origin.
Plant seedlings 60–75 cm (2–2 1/2 ft) apart. They can grow to 1 m (3 ft) high and, due to their weight, can be damaged by strong winds. Hill the soil up at the stem base as the plant grows to help overcome this problem.
Harvesting A cut-and-come-again vegetable, kale can be harvested starting at eight weeks.
Lacinato kale, often called Tuscan kale, is a chef’s favorite, with elongated, crinkly, dark gray-green leaves. Red Russian has scalloped, wavy leaves, which are blue-gray with a purple hue and reddish stems. Curly kale has heavily curled and scalloped leaves that are thicker and tougher than the others but still cook beautifully.
Remove the stem and shred 1 kale leaf (50 g) to yield 1/2 cup (35 g) firmly packed kale. Core and chop 1 green apple, slice 1 frozen banana, chop 3 dates, and grate a 1-cm (1/2-in) piece of peeled fresh ginger. Process in a blender with 1 1/4 cups (310 ml) coconut water. Makes 2 1/2 cups (625 ml)
Brassica oleracea Gongylodes Group
Also known as German turnip, turnip cabbage
This vegetable looks like it can’t decide whether to grow under the ground or above it. Its name is German for “cabbage turnip,” and its swollen base, which is actually the plant’s stem, develops above the ground, making it ideal for gardens that don’t have deep soils. Varieties with white, light green, or purple skins are available, and the foliage and base can both be eaten. The foliage is lightly steamed as a leaf vegetable. The base is peeled, and its white flesh, which has a sweet, nutty, turnip-like flavor, can be eaten raw, if picked young, or cooked.
The striking purple and white bulbs of kohlrabi, or turnip cabbage. The flesh is white in all varieties.
Sow seeds thinly in rows and thin out to 25–30 cm (10–12 in) apart after germination. To grow a continuous supply, sow every four to five weeks.
Harvesting Kohlrabi is ready for harvest 8 to 10 weeks after sowing, before the swollen base is the size of a cricket ball. It is best to thin out some plants early to spread the harvest. If allowed to grow too big, kohlrabi becomes tough and woody. It stores well in the refrigerator for more than a week and can also be peeled and diced for freezing.
Kohlrabi looks a little unusual, with its turnip-like base growing above ground and its cabbage-like foliage. It gives a relatively quick crop after 8 to 10 weeks.
Preparing kohlrabi
Kohlrabi is crunchy like a radish and tastes like a mild turnip or broccoli stems. Add it to a vegetable gratin or steam until just tender and drizzle with melted butter or olive oil, lemon juice, chopped fresh parsley, salt, and freshly ground black pepper.
To prepare kohlrabi for cooking, cut off the leaf stems and trim the base and top.
Peel off the thick outermost layer thoroughly with a vegetable peeler or knife. Beneath the hard skin is another fibrous layer, which should also be peeled away. Peel until you reach the crisp flesh, then thinly slice or cut into pieces as directed in the recipe.
