Growing, Cultivating and Propagating Ornamental Kale
Grow these “vegetables” for fall color
Head Cabbage is one of the most widely grown of the leafy vegetables. Along with its close relative, Kale, Cabbage is a cool-season crop, sown in spring for fall and winter harvest. It is a staple food in many European countries, and the principal ingredient of two well-known foods, cole slaw and sauerkraut.
The plants described and pictured here are close relatives of Head Cabbage, but are grown only for decoration and not for eating. They are edible, however, but have a rather bitter flavor. Even so, they can be used as a colorful garnish for salads, appetizer trays, or other dishes.
Ornamental Cabbage and Kale belong to the Acephala group of the species Brassica oleracea, a member of the Mustard family originally native to Southern and Western Europe. Head Cabbage, Broccoli, Cauliflower, and Brussels sprouts are also members of this species, but are in different groups. These are all cultivated plants with horticultural origins and are not found in the wild. The Ornamental Cabbages and Kales have been hybridized for their colors and leaf shapes at the expense of flavor.
There are a number of varieties of Ornamental Cabbage and Kale, which can be roughly divided into two groups: those having smaller leaves with smooth wavy edges, and those having larger leaves with heavily fringed, lacy edges. In both types, the outer leaves are always green or bluish-green. The central rosette is either white or cream, or shades of violet-pink or reddish-purple. There is a newer F1 hybrid called ‘Peacock’, with long, narrow, deeply cut leaves which give the plant a snowflake-like appearance.
How to grow Ornamental Cabbage and Kale
Ornamental Cabbage and Kale are annual plants grown from seed sown in late spring. They are outstanding for fall and winter color and can be used in many ways. When used as bedding plants, the leaf shapes and color combinations provide an interesting palette for unusual designs. They are ideal for pots, tubs, and window boxes, either by themselves in a mixture of the varieties, or planted together with fall-blooming plants such as Chrysanthemums. One effective method is to plant the different colors and varieties tight together in concentric circles, or other geometric patterns, in a large shallow bowl or tub.
Easy to grow from seed
Sow seed outdoors in late spring/early summer in trays, seed-beds, or uncovered frames. Cover the seeds lightly. They’ll germinate in 2-3 weeks at a temperature of 60°-65°F. Prick out the seedlings to individual pots as soon as they are large enough to handle. Plant them so that the cotyledons (seed leaves) are at soil level. Keep them in a sunny but cool location. The soil should be rich and well-drained; add some extra organic matter such as compost or leaf mold to regular potting soil.
Ornamental Cabbage and Kale need plenty of water and weekly feeding with dilute liquid fertilizer. They will grow rapidly and should be potted into larger pots (or their final location, if desired) as necessary. They can then be planted into the garden or tubs anytime during the growing season.
As the temperatures start to drop in late summer/early fall, stop fertilizing. The leaves will then begin to color up when the right temperatures drop to 50°F or below. The milder the climate, the longer they’ll continue to provide color.
Discard the plants when they begin to “bolt” (flower) later in winter or spring. You can let them flower and collect seed, it you wish, but it’s better to buy fresh seed each year.
Cabbage and Kale are subject to numerous problems from insects and diseases.
Keep an eye out for “chewers,” particularly Cabbage loopers and Cabbage worms. These will leave unsightly holes in the leaves (or no leaves, if the infestation is bad) which will spoil the plant’s appearance. Pick them off by hand and use an insecticide.
–Root maggots may infect seed beds; they are less of a problem on plants in pots later on. Plants will look wilted and begin to decline. Water with an insecticide.
–The club-root fungus can be a serious problem in garden beds, primarily where other cruciferous plants have been grown. As with root maggots, the roots are attacked and the plant will look wilted and may even die. Your nurseryman can also recommend a special fungicide to water in, but this may not help in advanced cases. Destroy the plants and remove the infected soil, and wait several years before planting Cabbages or their relatives in that spot again. Reducing the acidity of the soil by liming also helps.
NOTE: Pesticides not used according to label directions can be harmful to man, animals and plants. Use only pesticides that have labels with directions for home and garden use. Always read and follow label directions.
Ornamental Cabbage and Kale seed is available from mail-order seed catalogs and sometimes nurseries. Potted Plants are also often available from nurseries in fall.
Lifespan: An annual.
Season: Fall and winter.
Difficulty quotient: Easy, but pests and diseases can be a problem.
Size and growth rate
Fast-growing annuals with colorful leaves, which can be heavily fringed along the edges. Can grow to 12 inches or more across and about 12-15 inches high.
Flowering and fragrance
White or creamy yellow scentless flowers in a spike which “bolts” up from the center.
Light and temperature
Plants need full sun to keep their compact shape. The temperatures should be on the cool side though–in hot-summer areas a southern exposure is too hot. The leaves begin to color up in fall as the nighttime temperature drops below 50°F.
Watering and feeding
Ample water should be provided–never let plants dry out. Feed weekly with dilute liquid fertilizer during summer, but stop feeding towards fall.
Soil and transplanting
Use rich, well-drained soil that is neutral or slightly alkaline.
Use as bedding plants, or in large tubs, containers, or window boxes.