Kale, or leaf cabbage, is a cool weather vegetable that is grown for harvest of its edible leaves and as an ornamental plant. Kale forms upright leaves. Kales are grown primarily as foliage plants for their intensely colored leaves rather than as vegetables. 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 often grown 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. Kale is in the same species as a number of other cool season vegetables including Brussels sprouts, broccoli, cabbage and cauliflower.
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. 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. 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. Plants may also be grown in containers. Garden Uses. Mass plantings. Border fronts. Edging. Containers. In fall, mix with chrysanthemums, grasses and asters. Colorful leaves make an attractive food garnish. Hardy in zones 2 to 11.
Kale seeds require light for germination, so don’t cover them with soil. It is best to sow Kale seeds directly into the garden, where they are to grow. The exact timing for sowing and planting will depend on your local conditions. Sow Kale seeds about six to ten weeks before the first anticipated frost.
Plant the seeds in rows, spaced 18 to 24 inches apart, allowing 6 inches between seeds. Keep the soil moderately moist during germination.
The seeds will germinate and sprout in one or two weeks, depending upon weather and soil warmth.
When the young plants are about 3 inches tall, thin them out leaving the strongest and best plants spaced about 18 to 24 inches apart. Although Kale seeds can be sown indoors at any time of the year, without cool temperatures the plants won't attain much color. For starting seeds indoors, the seeds should be sown directly into a large 6-8 inch pot, to avoid the problems associated with transplanting.