Potato: holes eaten in leaves

What it is likely to be on potato

1. Slugs and snails

   Candidate 1common on this plant

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Slugs and snails
   • Agriculture and Horticulture Development Board — AHDB: Potatoes — slug damage

   Checked 2026-08-13

   The most destructive garden pest in a wet British spring, and the one surrounded by the most confidently repeated advice that does not work. They shred seedlings overnight and leave irregular holes with slime trails nearby.

   Points towards it

   • · slime on the lower leaves and grazed edges low down together point at something climbing from the soil rather than flying in
   • · heavy wet ground is what builds the populations that damage tubers and crowns, and it is the same ground that keeps them feeding
   • · damage concentrated in one damp corner of the row matches a slug population under a particular patch of ground rather than anything carried on the wind

   Argues against it

   • · they cannot cross dry open soil for long, and a baked bed suppresses them
   • · none of these five is grown indoors, so an indoor answer is about a different plant — this rules it out entirely.

   Check this next

   Treat the holes as a population count rather than as the damage. On a plant this size the leaves are expendable; what matters is that slugs are present in numbers where the crop is. Scrape the soil beside a potato ridge or pull back the mulch round a celeriac after rain and see how many you turn up, and lift one early potato in August and cut it — clean tunnels a few millimetres wide running into the flesh are the same animal, and that is the damage worth acting on.

   What to do now

   Act on the ground rather than on the leaves. Lift maincrop potatoes as early as the variety allows rather than leaving them in wet soil through September, which is when almost all tuber damage happens, and earth up so the tubers sit well covered. For celery and celeriac, keep the crown clear of decaying leaves and pull the mulch back from the stem base. Nothing needs doing about the foliage itself.

   ·source

   Sourced guidancehigh confidence

   • Agriculture and Horticulture Development Board — AHDB: Potatoes — slug damage and lifting date
   • Royal Horticultural Society: Slugs and snails — non-chemical control

   Checked 2026-08-13

2. Capsid bug

   Candidate 2occasional on this plant

   ·source

   Sourced guidancemoderate confidence

   • Royal Horticultural Society: Capsid bugs
   • Agriculture and Horticulture Development Board — AHDB: Potatoes — foliar pests

   Checked 2026-08-13

   A fast-moving green or brown bug, 6mm long, which feeds on shoot tips and is almost never seen doing it. What it leaves is unmistakable once the sequence is understood: it kills small patches of tissue in a leaf still folded in the bud, and as the leaf expands those patches tear into ragged holes with brown edges, so the finished leaf looks chewed and distorted while the plant never had a caterpillar on it.

   Points towards it

   • · capsids feed only in the growing tips, so damage on the top of the haulm with clean leaves below is close to diagnostic
   • · each feeding puncture kills a spot of tissue that later tears into a small ragged hole with a brown rim as the leaf expands
   • · capsids come in from hedges and adjacent weeds during summer

   Argues against it

   • · capsids leave nothing behind, so slime points at the other candidate for this sign
   • · damage confined to the lowest leaves is not from an insect that feeds only in the tips

   Check this next

   Look at the top of the haulm and at the shape of the hole. Capsid damage is at the growing tips with the lower leaves clean, and the holes are small, ragged and brown-edged, often puckering the leaf around them because the tissue died while the leaf was still folded and then tore as it opened. Slug damage on a potato is the reverse: large clean-edged windows on the lowest leaves, with slime.

   What to do now

   Nothing needs doing. Capsid damage on potato foliage looks alarming at the tips and does not measurably affect the crop, the insects have usually moved on by the time it is noticed, and the haulm grows past it within a fortnight. Keep the ground clear of tall weeds around the plot, which is where the bugs come from, and check the tips again in two weeks — if fresh damage is still appearing on new leaves it is worth looking for the bugs at dusk, but a static patch of ragged tips is finished.

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Capsid bugs — control

   Checked 2026-08-13

Narrow it down

This page lists everything at once, which is the right shape for reading and the wrong shape for deciding. The interactive tool asks one question at a time, starting with whichever would separate these causes fastest, and stops as soon as further answers would not help.

Opens with the plant and the symptom already set. Nothing you answer is stored or sent anywhere — the answers live in the address bar and nowhere else.

What this does not cover

These are the causes GrowingHQ holds rules for on potato — not every cause there is. Where several problems look alike, the honest answer is often that they cannot be told apart by eye, and a page that named one would be guessing. If none of the above fits, the general holes eaten in leaves page lists causes across all plants, and the Potato profile lists the problems it is prone to.