What's eating my allium 'firmament'?

Allium 'Firmament', a mid-sized ornamental allium, is largely pest-resistant due to its sulfurous compounds. Allium leaf miner poses the greatest risk in UK and European-influenced US climates. Onion thrips and slugs are minor secondary concerns on young foliage. Deer and rabbits reliably avoid it — a useful natural deterrent in the border.

Rows of white feeding spots on leaf surfaces; larvae tunnel into the plant base and bulb, causing rot. Exclude flying adults with insect-proof fleece during spring and autumn. Dig up and bin infected plants; rotate allium positions annually.

Pale silvery streaks on the strap leaves; heavy infestations reduce photosynthesis and flower stem vigour. Spray with neem oil or insecticidal soap; remove affected leaves; avoid nitrogen-heavy feeding that attracts thrips.

Chewed holes in soft new foliage as it pushes through the soil in early spring. Apply iron phosphate pellets; use copper-edged raised beds; hand-pick after dark when slugs are most active.