What's eating my spring onion?

Spring onions are vulnerable to onion fly maggots, thrips, and allium leaf miner, as well as slugs on young seedlings. The short growing cycle limits window for damage but onion fly can destroy a whole row fast. In the US, western flower thrips are also common. Row covers from sowing are the most reliable control.

Leaves wilt and yellow; white maggots tunnel into the base and roots, causing complete plant collapse Sow under insect-proof mesh; avoid disturbing soil near alliums (scent attracts females); avoid growing near onion fly-prone areas of the garden

Silver-white flecking or streaking on leaves; tips die back; plants look bleached in severe cases Spray with insecticidal soap or neem oil; remove weeds that harbour thrips; avoid overhead irrigation that leaves moisture on leaves

Rows of white feeding punctures on leaves; larvae mine inside leaf tissue, disfiguring the crop Cover with fine insect-proof mesh during spring and autumn adult flight periods; destroy affected material