What's eating my kohlrabi?

Kohlrabi swells fast but its tender skin and brassica foliage attract flea beetles on seedlings and caterpillars through summer. Slugs damage the swelling stem base in wet conditions. In the UK, cabbage root fly is a real threat to transplants. Aphids colonise growing tips and can distort the swelling globe if unchecked early.

Shotgun-pattern tiny holes across seedling leaves; young kohlrabi seedlings are particularly vulnerable at the cotyledon and first-true-leaf stage. Row covers immediately after sowing or transplanting. Diatomaceous earth along rows. Spinosad spray if damage is severe. Sow later in summer to miss peak spring flight.

Eats leaves and occasionally bores into the developing swollen stem, leaving frass-filled tunnels that rot the kohlrabi globe. Insect-proof netting is most reliable. Bt spray on leaves in the evening. Remove egg clusters from leaf undersides weekly.

Irregular surface feeding on the swelling globe at soil level, creating entry points for bacterial rot that ruins the entire harvest. Raise planting on mounds to improve drainage. Iron phosphate pellets around plants. Beer traps. Hand-pick after dark. Avoid wet mulch against stems.