Why Are There Holes or Notches in My Garlic Leaves?

Garlic's strong scent makes it one of the more pest-resistant crops — it is often grown specifically to repel pests from other plants — so holes or notches chewed in the leaves are relatively unusual and worth identifying. A few specific pests do target alliums, and knowing which one helps you protect the crop. Let me walk you through the likely culprits.

Leek moth and allium leaf miner

The pests most likely to damage garlic foliage are the allium specialists. The leek moth and the allium leaf miner both lay eggs on alliums, and their larvae tunnel and mine within the leaves, causing whitish patches, notches, holes and lines of damage, and sometimes burrowing down toward the bulb. You may see small caterpillars or maggots within the leaves, and rows of tiny scars. These pests are increasingly common in some regions and can seriously damage garlic. The main defence is covering the crop with fine insect mesh at the times the adults are active to prevent egg-laying, plus removing and destroying affected leaves, and rotating alliums.

Slugs and snails

Slugs and snails occasionally rasp or hole garlic leaves, especially young growth in damp conditions, leaving ragged damage and slime trails. Garlic is not their favourite, so damage is usually minor compared with leafy crops, but seedlings and soft spring growth can be nibbled. Standard slug control — hand-picking at night, traps, clearing damp hiding places, and gritty barriers — handles them if they become a problem.

Birds and physical damage

Birds sometimes tug at or peck garlic shoots, particularly newly emerged ones in spring, occasionally pulling them up or notching the leaves. Covering young plants or using bird deterrents protects them. Physical damage from wind, hail, or treading can also tear and notch garlic leaves, which looks like pest damage but is mechanical — the plant grows on from such damage without trouble.

Identifying and protecting

Match the damage: whitish mined patches, holes and small larvae within the leaves point to leek moth or allium leaf miner — cover with mesh and remove affected leaves; ragged holes with slime mean slugs — use standard slug control; tugged, pulled or pecked shoots mean birds — cover or deter. For the serious allium pests, fine insect mesh over the crop during the adults' active periods is the key defence, along with allium rotation and good garden hygiene. Most garlic, though, comes through the season with little pest damage thanks to its own pungency.