What's eating my kohlrabi 'kolibri'?

Kohlrabi 'Kolibri' — a compact purple variety — faces the same Brassica pest lineup as other kohlrabi: flea beetles, cabbage worms, aphids, and slugs are the main threats. The purple pigment offers no pest resistance. Flea beetles do the most damage to seedlings; row covers prevent most problems.

Hundreds of tiny pinholes in seedling leaves; heavy pressure kills young transplants before they establish Row cover applied at transplanting; kaolin clay spray as a physical deterrent; pyrethrin as a last resort

Ragged holes and frass on outer leaves; caterpillars sometimes bore toward the developing bulb Bt-k spray weekly during peak butterfly flight; hand-pick egg clusters (pale yellow, laid singly on leaf underside)

Grey waxy colonies on leaf undersides and stem; distorted leaves; slow plant growth Water jets, insecticidal soap, or neem oil; avoid high-nitrogen fertilizer which favors aphid outbreaks

Overnight leaf damage with slime trails; young bulb skin can be scarred by surface grazing Iron phosphate bait (pet-safe); copper tape around raised beds; hand-pick at dusk