Gardening Articles: Edibles :: Vegetables
Bravo for Brassicas
by Susan Littlefield
The New Year is a time for resolutions and one of the most common is the vow to eat a more healthful diet. An easy and delicious way to do this is to include more brassicas, or members of the cabbage family, in your diet -- and your gardens. Homegrown broccoli, cabbage, cauliflower, Brussel's sprouts, kale, collards and kohlrabi make for delectable eating when picked fresh from the vegetable garden and served raw, roasted, lightly steamed or stir-fried. And they are all some of the most nutritious crops you can grow. Not only loaded with vitamins, minerals and fiber, cabbage family members are also especially high in the phytochemicals that act as antioxidants to protect against cancer, diabetes and heart disease. So plan now to include some of these "super-veggies" in your garden this spring.
The cabbage family clan, also known as cole crops, are all, surprisingly, variations on one species, Brassica oleracea. Selective breeding over hundreds of years has produced the variety of crops we now cultivate, including B. o. variety capitata (meaning "head") or cabbage, and B. o. variety acephala (meaning "without a head") or kale and collards. Chinese cabbages are brassicas too, but are different species (B. rapa) more closely related to turnips. While the timing of planting and their use in the kitchen may vary, all these relatives need similar cultural conditions. They all do best when grown in fertile, humus-rich soil in the cool (but not too cold) temperatures of spring and fall.
Broccoli and cabbage are probably the two most popular cole crops for home gardeners, both for their taste and versatility in the kitchen as well as their ease of cultivation.
While you can direct seed broccoli right in the garden, success is more assured if you start seeds indoors and transplant seedlings to the garden when they are large enough to better weather insects pests and outdoor temperatures. Start seeds 6 to 8 weeks before the last frost date in your area; transplant hardened off seedlings into the garden two weeks before the the last frost date. For a fall crop, sow seeds 10 to 12 weeks before the first fall frost date. Gardeners in mild winter climates can sow succession crops in the fall for harvest throughout the winter.
Broccoli is a heavy feeder so work a few inches of organic matter into the soil before planting. Soil pH between 6.0 and 7.2 is ideal. Space seedling 15-18 inches apart and set them slightly deeper than they were growing in the container, up to their first set of true leaves. Protect the stem of each plant with a cutworm collar. The simplest way is to wrap the seedling stem with 2- to 3-inch strips of newspaper. Cover the seedlings with a floating row cover to prevent damage from flea beetles and cabbage worms. If the temperature dips below 50 degrees for more than one night, add some extras layers of row covers to prevent chilling injury.
Get your broccoli off to a good start with a sidedressing of a soluble fertilizer about 2 weeks after transplanting and again just as the heads begin to form.
Broccoli is ready to harvest as soon as the head, which is actually a cluster of unopened flower buds, is of a usable size and has a deep green color. Cut the main head with a 2 inch stem, then check for the formation of smaller side shoots that will extend your harvest.
Growing rapini is a little different than growing heading broccoli. Direct sow as soon as the soil can be worked in the spring, spacing seeds 1-2 inches apart and thinning to 6 inches. Harvest this fast-maturing crop when stems are about a foot tall and flower heads about an inch across. For a fall crop, sow seeds in late summer and early fall, making succession plantings up until about 3 weeks before the first fall frost.