Latin Name: Brassica oleracea
Type: Open Pollinated, Heirloom, Cool Season
USDA Zones: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
Seeds per Ounce: 9,000
Planting Method: Direct Sow
Sunlight: Full Sun
Height: 16 Inches
Color: Purple
Purple Vienna is a standard home garden and market kohlrabi variety with deep purple skin and crisp greenish-white flesh. The mild flesh is great cooked or fresh. The bulbs become fibrous as they mature, so for best quality, harvest at 2" in diameter, which takes about 55 days from sowing.
Named for a German word meaning "cabbage turnip," kohlrabi was developed first around the 16th century in northern Europe. By the end of that century, it had spread throughout the rest of the continent as well as to the Mediterranean region. The first recorded mention of kohlrabi in the States is found in the early 16th century. More recently, the countries of China, Israel, and Africa have discovered this vegetable; it has become quite a staple of northern Indian cuisine. Purple Vienna heirloom kohlrabi in particular dates back to 1863.
GROWING INFORMATION
Sowing:
Though kohlrabi grows best in cool weather, a continuous crop from spring to fall will grow in most climates. Direct sow purple Vienna kohlrabi seeds in rich soil and full sun 2-3 months before the last spring frost, or when the average soil temperature reaches at least 50 degrees F. Plant the seeds 1/4" deep with ten seeds per foot; thin plants to 5" apart in rows 1' apart. For a continuous crop, plant new seed every few weeks until six weeks before the first frost of autumn. Gardeners with the benefit of warmer winters can plant seed in late winter for an early spring crop. For companion planting benefits, plant kohlrabi with onions, beets, or cucumbers; avoid planting it with strawberries or tomatoes.
Growing:
Success with kohlrabi depends on adequate moisture and good soil; the best flavor and tenderness are achieved when kohlrabi is able to grow quickly. Keep the soil moist and control weeds by applying mulch. Watch out for aphids, maggots, and other pests that will damage the crop.
Harvesting:
For best tenderness, harvest kohlrabi when their diameter reaches a size of 2-3 inches. Pull the whole plant and remove the leaves and roots. Kohlrabi keep well in the refrigerator for up to a month.
Seed Saving:
Since kohlrabi will cross pollinate with other members of the cabbage family such as broccoli or cauliflower, separate it to preserve genetic purity. Late in the fall, dig up the plants being saved for seed; remove the leaves and stem, and cut the root to 4-6" long. Keep the plants in moist sand at a temperature of about 40 degrees F. Replant the best plants 4-6 weeks before the last spring frost. The stem will grow about 4-5' tall, with many four petaled yellow flowers. Allow the flowers to mature; when the seed pods form, pick them and allow them to dry. Remove them from the pods and store purple Vienna kohlrabi seeds in a dry, cool place for up to five years.