Common Name: kale
Type: Annual
Family: Brassicaceae
Zone: 2 to 11
Height: 1.00 to 1.50 feet
Spread: 1.00 to 1.50 feet
Bloom Time: Flowers not showy
Bloom Description: Rarely flowers
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Annual, Vegetable
Flower: Insignificant
Leaf: Colorful, Good Fall
Culture
Easily grown in organically rich, consistently moist, well-drained loams in full sun. Ornamental cabbage and kale are cool weather plants that need cool temperatures to produce best leaf colors. In St. Louis, they are best grown in the cool temperatures of fall, but may also be grown in early spring. If grown in summer, however, plants will need some afternoon shade, perhaps to survive, but the foliage will fail to produce good leaf color in the absence of cool temperatures. Plants generally grow poorly when daytime temperatures begin to consistently exceed 80°F. Cultivars may often be grown from seed or plants may be purchased in cell packs from nurseries. For fall display, start seeds indoors around July 1. Seedlings may be planted outdoors around mid-August. Foliage remains attractive well into fall including through several frosts. Depending on temperatures, plants may survive until Thanksgiving or into December in some years. In mild winter climates, plants often survive winter and remain attractive until they bolt in spring. Promptly remove any flower stems that may appear. Plants may also be grown in containers.
Noteworthy Characteristics
Brassica oleracea (Capitata Group), commonly known as cabbage, and Brassica oleracea (Acephala Group), commonly known as kale, are cool weather vegetables that are grown for harvest of their edible leaves. Cabbage forms heads and kale forms upright leaves. Ornamental cabbages and kales are grown primarily as foliage plants for their intensely colored leaves rather than as vegetables. Ornamental plants were developed for ornamental use without regard to taste. Ornamental cabbage typically develops large rosettes of broad flat leaves and ornamental kale typically develops curly, ruffled leaves in a tight rosette. Leaf colors are usually quite showy, including white/cream, pink, rose, red and purple. These are biennials that are grown in St. Louis as annuals. Plants will grow to 12-18” tall. Plants need the cool weather of spring or fall to develop their best foliage color. As night temperatures drop during the fall, the leaf color typically darkens and intensifies. Cabbage and kale are in the same species as a number of other cool season vegetables including Brussels sprouts, broccoli, cauliflower and kohlrabi.
Genus name comes from the classical Latin name for cabbage.
Specific epithet means of vegetable gardens.
'Redbor' features purple-red leaves. It is primarily grown in gardens as an ornamental foliage plant rather than as a vegetable. The curled purple-red leaves with silver tones add intense color, texture and interest to garden areas. It is a biennial that is grown in St. Louis as an annual. Plants will grow to 18" tall. Plants need the cool weather of spring or fall to develop their best foliage color. As night temperatures drop during the fall, the leaf color of ‘Redbor’ darkens and intensifies.
Problems
Watch for cabbageworms, cabbage loopers, flea beetles, caterpillars, thrips, slugs, and aphids. Root maggots may be a problem in some areas. Potential disease problems include leaf spots, blackleg, black rot and yellows.
Uses
Border fronts, ornamental garden areas, edging, window boxes, containers. Mix with chrysanthemums, grasses and asters. Leaves may be harvested as a vegetable, but taste is somewhat inferior to that of kales developed for vegetable gardens. Red leaves may be used as an attractive garnish.