Kohlrabi Growing Guide Brassica oleracea var. gongylodes Crop Rotation Group Brassicas (Cabbage family) ● Soil Rich soil, light textured with plenty of well rotted compost dug in. Position Sun preferred. Frost tolerant Yes, tolerates mild frosts. Feeding Not required if good soil but can still benefit from organic compost mixing in before planting. Spacing Single Plants: 25cm (9") each way (minimum) Rows: 20cm (7") with 30cm (11") row gap (minimum) Sow and Plant Sow in early spring either direct into soil or in pots to plant out later. Our Garden Planner can produce a personalised calendar of when to sow, plant and harvest for your area. Notes May require fine mesh or exclusion netting over the warmer months to prevent butterflies laying eggs on the underside of leaves but usually matures quickly enough for this not to be a problem. Harvesting Harvest from mid summer onwards when roots are up to tennis ball size to prevent the texture becoming 'woody'. Planting and Harvesting Calendar < Back to All Plants Pests which Affect Kohlrabi Aphids (General) Cabbage Moth Cabbage White Butterfly Diamondback Moth Flea Beetle Slug Snail Plant Diseases which Affect Kohlrabi Brassica Alternaria Leaf Spot Brassica Club Root Brassica Downy Mildew