Earwig Damage Has a Look, but It Is Easy to Blame Them for the Wrong Problem
Earwigs get accused of nearly every chewed leaf in a garden. I have seen gardeners set traps after finding ragged holes in hostas, only to discover a fat slug under the mulch the next morning. Earwigs do eat plants, especially tender seedlings, petals, soft fruit, and new leaves, but they also eat aphids, mite eggs, small caterpillars, and decaying material. Finding one under a pot does not prove it caused the damage.
The useful question is not “Are earwigs present?” They usually are. The question is whether the feeding pattern, the timing, and the hiding places all point to earwigs.
What Earwig Feeding Usually Looks Like
Earwig damage tends to look messy rather than neatly patterned. On leaves, expect uneven holes and chewed edges with irregular, torn-looking margins. The holes may be large enough to notice, especially on young bean plants, basil, lettuce, dahlias, zinnias, and seedlings that have only a few leaves.
They often work on the softest tissue first. A plant may have healthy older leaves but a badly shredded center where fresh growth is emerging. On flowers, earwigs chew petals from the edges inward, leaving blooms with scalloped, ragged sections. Dahlias and marigolds are frequent targets because the petals offer a sheltered, tender food source.
On fruit, look for shallow, rough cavities rather than a clean puncture. Earwigs are especially attracted to fruit that is already splitting, overripe, or damaged by birds or insects. They can enlarge that damage, but they are often not the original cause.
A damaged leaf tells you what happened. A damaged leaf plus earwigs hiding nearby at dawn tells you who probably did it.
The Timing Is Often the Best Clue
Earwigs are mostly active at night. During the day, they wedge themselves into narrow, damp, dark spaces: beneath mulch, under boards, inside folded leaves, around the bases of pots, in dense groundcover, and between fruit clusters.
If you inspect plants at 2 p.m. and see no insects, that does not rule them out. Check after dark with a flashlight, or go out just before sunrise. Lift nearby pots, turn over mulch, and inspect the underside of damaged leaves.
A realistic example: one June, a row of six-inch-tall bean seedlings was losing leaf edges almost overnight. The plants looked fine at sunset, but by morning several had half-moon-shaped bites and two seedlings had been chewed down to stems. At 5:30 a.m., there were clusters of earwigs packed beneath the wooden edge of the raised bed, less than a foot from the beans. The bed had thick damp leaf mulch and a dripping irrigation fitting. Removing the wet mulch from the seedling row and fixing the leak solved most of the issue within a week.
How to Separate Earwig Damage From Other Garden Pests
Earwigs versus slugs and snails
Slugs leave irregular holes too, so this is the most common mix-up. The deciding clue is slime. It may be faint, but look closely in morning light along leaf edges, on soil, and across nearby mulch. Slugs also favor very damp conditions and often leave holes between leaf veins, creating a lacy look.
Earwig feeding usually has no slime trail. If you find black, pepper-like droppings, slug slime, and a slug tucked beneath a leaf, do not blame earwigs just because you saw one elsewhere in the bed.
Earwigs versus caterpillars
Caterpillars often leave larger holes, visible dark droppings, and chewed areas concentrated on a particular plant. Look along stems, beneath leaves, and inside curled foliage. A caterpillar may be perfectly camouflaged but usually stays on the plant it is eating.
Earwigs tend to retreat into cover by daylight. Their damage may appear on several nearby plants rather than one leaf loaded with frass.
Earwigs versus flea beetles
Flea beetles make many tiny, fairly round “shot holes,” especially in eggplant, radish, arugula, and brassicas. Earwigs make fewer, more irregular holes and broader bites along edges. If the holes look as though someone used a small hole punch, flea beetles are the better suspect.
Where Earwig Damage Is Most Likely to Matter
A few chewed leaves on an established hosta, rose, or tomato plant are usually not worth treating. Healthy mature plants can outgrow cosmetic damage easily. Earwigs also may be cleaning up dead material or eating pests you have not noticed.
The damage becomes important when it affects plant survival or harvest quality. Watch closely around:
- newly transplanted vegetables and annual flowers
- lettuce, basil, and other crops harvested for their leaves
- opening dahlia, zinnia, and marigold blooms
- ripening stone fruit, berries, and corn ears
- plants growing beside dense mulch, stacked pots, boards, or constantly wet irrigation zones
The non-obvious part is that a high earwig count is not automatically bad. A dry, established flower border can support plenty of earwigs with no meaningful plant damage. In fact, broad insecticide use there can create a bigger aphid problem by killing the predators along with the earwigs.
A Quick Way to Confirm the Cause
Use a simple overnight trap before taking action. Roll up a sheet of damp newspaper, use a short piece of corrugated cardboard, or place a small upside-down flowerpot stuffed loosely with straw near the damaged plants. Set it in the evening and check it early the next morning.
If several earwigs are sheltering inside and fresh damage is concentrated within a few feet of the trap, you have a strong confirmation. Move the trap away from valued plants and empty it into a compost pile or a less sensitive area of the yard. Repeat for several mornings if needed.
Quick identification checklist
- Irregular holes or ragged leaf edges, not neat pinholes
- Damage appears after overnight feeding
- No visible slime trails
- Earwigs found beneath nearby damp, tight cover at dawn
- Worst damage on seedlings, petals, or soft fruit
- Dense mulch, clutter, or excess moisture around the affected plants
What I Would Fix First
Do not start with pesticide. Start by making the immediate area less comfortable. Pull mulch back two to three inches from small seedlings, remove wet piles of leaves, lift unused pots off the ground, and repair drippers that keep one spot damp all day. Harvest ripe fruit promptly and remove fallen fruit before dusk.
For vulnerable seedlings, a fine mesh cover or a simple collar can buy enough time for the plants to toughen up. I am more aggressive with protection for basil and bean starts than I am with a mature ornamental plant. Once stems firm up and leaves are no longer the only food source, earwig damage usually becomes far less dramatic.
The common mistake is treating every earwig sighting as an infestation. Confirm fresh feeding, inspect at the right time, and protect the plants that actually need protecting. That approach keeps the garden healthier and saves a lot of unnecessary effort.
