University of Vermont Extension 
Department of Plant and Soil Science

Summer News Article

Dr. Leonard Perry, Extension Professor
University of Vermont
Most think of cabbage and kale merely as vegetables, but they make great garden annuals as well for their fall foliage.  For these various uses, the National Garden Bureau has named them vegetables of the year for 2007, and has provided some interesting information and cultural tips.

Cabbage and kale grow best in cooler weather, so usually are seen in gardens early or late in the season.  For fall harvest, sow seeds in July or buy seedlings in August.  Mature plants with ornamental leaves can be found in late August and September at many garden centers.  These combine well with fall mums.  If buying mature plants, look for ones with leaves to their base.  Ones with tall stems and no leaves, a tree effect, are signs the plant didn’t get enough water or fertilizer.

When buying seedlings or mature plants, look under the leaves and along the stem for any sign of insects or insect damage, especially aphids. If you see small white moths with a black dot on their wings hovering, these are likely cabbage moths, which lay their eggs on the plants; don’t buy these plants. Avoid rootbound plants or ones with roots hanging out the bottom of the pot or cell pack.

Set the plants at least 12 inches apart; space rows 24 to 36 inches apart, depending on the variety. To get the plants off to a good start and encourage root development, pour in one cup of a soluble starter fertilizer (diluted according to package directions) to each planting hole before
filling it in. To avoid cutworm damage, place a tuna fish or cat food can (with top and bottom removed) halfway into the soil around stems to act as a collar for the seedling plant.

Keep plants lightly moist. This is especially important for plants started in the summer for fall and winter harvest. Side dress with nitrogen fertilizer when the plants are half grown, or foliar feed every three weeks. Mulch with one to two inches of organic matter, keeping the mulch an inch away from the stem of the plant. Mulching helps keep the soil moist, feeds the plants, and controls weeds. Irrigation is especially important to help the young plants withstand the intense sunlight and heat of summer, and to supply the developing heads with sufficient water to develop quickly.

Among the most common pests are aphids and cabbage loopers. The small white moths in the gardens lay eggs that turn into cabbage loopers. Cover the plants with screening or floating row cover to prevent this. Control aphids by spraying with frequent hard blasts of water; try spraying with insecticidal soap or hot pepper spray.

You can harvest cabbage anytime after the heads form. Cut the heads when they are solid (firm to pressure) but before they crack or split. Springy heads are not mature.  Store late fall or winter cabbage for several months in humid conditions as close to freezing as possible. Store only disease-free heads. Pull out the cabbages and hang in a moist cellar, roots and all, or cut heads, remove loose outer leaves and spread one layer deep on shelves or pallets in a moist root cellar.

Pick outer leaves of kale as you need them and plants will keep producing new inner leaves. Harvest when leaves are large enough for intended use. Tender young leaves are best for salad, older leaves for cooking. Frost improves the flavor of kale. Mature plants survive to ten degrees F or below. Mark the site so you can find the fresh greens under the snow.

Dark green leafy cabbage is high in Vitamin C, iron, and folate. Cabbage also contains beta-carotene, potassium, and phyto-chemicals, such as glucosinolates—proven to reduce cancer, especially lung cancer. The pale center leaves are much less nutritious. Avoid overcooking as this depletes the nutritional content. Raw red, green, or Savoy cabbage has about 20 calories a cup, or cooked it is 30 calories.  Chinese cabbage is only 11 calories a cup raw or 15 cooked, and is higher in Vitamin C than the other cabbages.

Whether raw or cooked, kale is a low calorie, high nutrition leafy green. A cup of raw kale has 60 calories; cooked it is 48 calories. Even cooked, where it can lose one-third or more of its nutritive value, a cup of kale provides the minimum daily requirement of Vitamins A and C and 13 percent of the calcium requirement. A good source of glucosinolates, Vitamin E, and manganese, kale is used as a green vegetable, steamed and served with butter or vinegar, or in soups. Unfortunately, kale is often used in salad bars as the decoration covering the ice rather than as a selection on its own.

Consider adding cabbage and kale to your vegetable or flower garden, or both, this year.  You’ll have a nutritious crop, and the ornamental-leaved varieties last well into late fall, through frosts and even light snow.


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