Guides
What is eating holes in my plant leaves?
Many leaf-eating pests hide during the day. Use the hole shape, its position on the leaf, and any slime trails or droppings nearby to narrow the cause.
Check after dark
Where the ground stays damp, much of the feeding happens between dusk and dawn. Check the plant after dark for slugs, snails, vine weevil adults and caterpillars. In a hot dry garden, also check during the day for beetles and grasshoppers.
Work down the list
Slugs and snails
- What you would see
- Ragged holes with no straight edges, often started at the leaf margin, on soft low growth. Seedlings and hostas taken to the stalks overnight.
- The check
- Look for slime trails on the soil, the pot and the stems in the morning light. A silver slime trail points to slugs or snails.
Caterpillars
- What you would see
- Holes through the middle of the blade or the whole leaf gone, with dry pellets of frass caught in the plant below the damage.
- The check
- Turn the leaves over and look along the midribs. Then count the fleshy legs behind the front three pairs. Five pairs or fewer is a moth or butterfly caterpillar.
Sawfly larvae
- What you would see
- A row of grubs feeding shoulder to shoulder along a leaf edge, and a gooseberry, rose or aquilegia stripped in a fortnight.
- The check
- Count the legs again. Six or more pairs of fleshy prolegs means a sawfly. Caterpillar treatments will not work on sawfly larvae.
Flea beetles
- What you would see
- Dozens of small round holes and shallow pits peppered over the upper surface, worst on seedlings of rocket, radish and brassicas, which can end up looking sandblasted.
- The check
- Stand still over the row for half a minute. Dark beetles 2 to 3 mm long come back to the leaves and spring away again the moment your hand moves. That jumping is the clue.
Vine weevil adults
- What you would see
- Small clean notches bitten out of the leaf margin, each about the size of a match head, leaving the rest of the leaf whole.
- The check
- Look at rhododendron, euonymus, bergenia and anything in a container. The notching is cosmetic; the root-eating grubs below are the more serious stage.
Box tree caterpillar
- What you would see
- Box leaves eaten to a papery skeleton, fine white webbing binding the shoots, and bare brown patches spreading inside the hedge.
- The check
- Part the foliage and look at the centre of the plant. If only the box is damaged and nearby plants are untouched, box tree caterpillar is the likely cause.
Lily beetle
- What you would see
- Holes through lily and fritillary leaves, buds and flowers, with wet black blobs stuck to the undersides.
- The check
- A bright scarlet beetle on the leaf confirms it. It often drops to the soil when disturbed, so cup a hand underneath before picking it off.
Leaf miners
- What you would see
- A pale squiggle or a brown blotch where the leaf looks eaten but both surfaces are still intact over the top of it.
- The check
- Hold the leaf up to the light. A hollow chamber with a dark thread of droppings inside is a mine rather than a hole.
Shot hole from leaf spot
- What you would see
- Small round holes with brown or grey rims, evenly scattered, on a plant nothing has visibly chewed.
- The check
- Look at the edge of the hole. A shot hole from a leaf spot has a neat dead rim where the tissue died before it fell out. A chewed edge is ragged and green.
Birds
- What you would see
- Whole leaves and buds stripped from brassicas or fruit bushes in winter, or new growth pecked out in spring.
- The check
- Look for droppings and footprints instead of frass, and for damage that appeared in daylight while you were out. Fit netting before the damage starts.
Still not sure which one it is? Photograph the leaf and compare it against the full library.