General
This close relative of the cabbage was bred over centuries to develop a flattened meristem. Sometimes referred to as German turnips, kohlrabis are very rich in vitamin C, and a great source of potassium. The flavour is like a very mild cabbage and the texture is crisp and crunchy, a bit like that of a pear.
Latin
Brassica oleracea var. gongylodes
Family: Brassicaceae
Difficulty
Easy
Season & Zone
Season: Cool season
Exposure: Full-sun
Zone: 3-10
Timing
Direct sow early April until mid-May for a crop to mature in about 8 weeks. Sow again mid-July to early August for fall and winter crops. Planting between mid-May and mid-July causes them to mature in hot weather resulting in inferior bulbs. Optimal soil temperature for germination: 10-30°C (50-85°F). Seeds should germinate in 7-10 days.
Starting
Sow seeds 5mm (¼") deep with plants spaced 10-15cm (4-6") apart in rows 30-45cm (12-18") apart.
Growing
Ideal pH: 6.0-6.8. Kohlrabi is a moderate to heavy feeder that does best in humus-rich soil amended with composted manure. Mix ¼-½ cup complete organic fertilizer into the soil under each plant.
Harvest
Spring-sown kohlrabi will get larger than tennis balls in fair soil, but if you pick them when they are still less than 5-8cm (2-3") in diameter they will be sweet and
tender. Fall-grown kohlrabi can grow larger yet stay tender. Kohlrabi is frost-hardy, and may last well beyond Christmas in the garden.
Seed Info
In optimal conditions, at least 80% of the seeds will germinate. Usual seed life: 3 years. Per 100' row: 360 seeds, per acre: 104M seeds.
Diseases & Pests
Protect from cabbage moths and other insect pests with floating row cover. Prevent disease with a strict 4-year crop rotation, avoiding planting Brassicas in the same spot more than once every four years.
