How to tell whether earwigs are actually eating your seedlings
Earwigs get blamed for a surprising amount of garden damage they did not cause. They are active at night, they hide under pots and mulch during the day, and they look dramatic enough to become the obvious suspect. The truth is that earwigs will chew tender seedlings, especially lettuce, basil, beans, marigolds, dahlias, and young brassicas. But they also eat aphids, insect eggs, and decaying plant material, so wiping them out across the whole garden is usually a bad trade.
The first thing I check is the pattern of damage. Earwig feeding usually shows up as ragged, uneven bites on leaf edges or soft holes in the middle of a leaf. The newest leaves may look scalloped or shredded by morning, while the stem remains intact.
A seedling cut cleanly at soil level is more likely a cutworm. Small, tidy “shot holes” usually point to flea beetles. Large irregular holes paired with silvery slime trails are slugs or snails. If a seedling is disappearing overnight and the soil around it is damp, covered with mulch, or packed with hiding places, earwigs become more likely.
The giveaway is not merely finding earwigs nearby. The giveaway is finding them hiding close to damaged plants, then seeing fresh chewing stop after you remove their daytime shelter.
A realistic garden situation: the damp lettuce bed problem
In one spring vegetable bed, newly transplanted lettuce was being hit hard over a four-day stretch. The plants had been set out in the evening, watered deeply, and covered with a thick layer of shredded leaf mulch. By 7 a.m., several leaves on each plant had ragged chunks missing. One small romaine lost almost half its outer leaves.
At first glance, slugs seemed likely. There was no slime, though. A quick check at 10 p.m. with a flashlight found earwigs clustered beneath the wet mulch and inside the folded leaves closest to the ground. The bed had also been watered with a sprinkler late every evening, which kept the whole surface cool and wet through the night.
The fix was not an insecticide. The mulch was pulled back about 3 inches from each lettuce crown, watering was moved to early morning, and rolled-up damp newspaper was placed near the bed as a trap. Each morning for a week, the newspaper rolls were shaken into a bucket of soapy water. Damage dropped sharply after three nights, and the lettuce recovered without replacing a single plant.
Remove the conditions that make seedlings easy targets
Earwigs like dark, moist, tight spaces. If your seedlings are sitting in a miniature earwig hotel, the population builds fast. This is especially common around raised beds with heavy mulch, stacks of pots, damp boards, landscape fabric, and trays left directly on the ground.
Give seedlings a dry, open buffer
You do not need bare soil everywhere. Mulch is useful, particularly in hot weather. The practical move is to keep a small clear ring around very young plants until they have several sturdy leaves. A 2- to 4-inch gap between mulch and the seedling stem makes it harder for earwigs to hide right beside the food source.
Water early in the day when possible. Overnight watering does not automatically create an earwig outbreak, but it keeps the surface damp during their feeding hours. Drip irrigation is better than spraying the entire bed because it gives the roots water without soaking every hiding place.
Clean up the hiding places that matter
- Lift flat boards, unused pots, seed trays, and overturned buckets near damaged plants.
- Move dense mulch, wet leaves, and grass clippings away from seedlings.
- Empty saucers under outdoor containers after watering.
- Harvest overripe fruit and remove decaying plant debris, especially around strawberries and herbs.
- Keep compost piles and wood stacks away from the most vulnerable seedling beds if earwig pressure is high.
A common mistake is stripping all mulch and debris from the entire garden. That can dry out the soil, disturb beneficial insects, and create more work than necessary. Focus on the first foot around seedlings and the places where you actually see earwigs hiding.
Use traps to find the source, not just to catch a few insects
Traps are useful because they answer an important question: are earwigs concentrated in this bed, or are they merely passing through? Put out several traps, not one. Place them beside the damaged plants, near the bed edge, and near any likely shelter such as a pot stack or mulch pile.
Simple overnight traps that work
Roll a sheet of newspaper loosely, dampen it, and place it on the soil before sunset. Short pieces of garden hose, cardboard tubes, or a small bundle of dry straw also work. Earwigs crawl into these spaces before daylight. In the morning, carry the trap away from the bed and shake the earwigs into a bucket of soapy water, or relocate them far from tender plants if the numbers are modest.
If you catch dozens in one trap for several mornings, you have confirmed a local sheltering problem. Inspect within a few feet of that trap. In practice, the source is often a wet mulch layer, a stack of nursery pots, a leaky hose connection, or a board that has not been moved all season.
Oil traps can catch earwigs too, but I do not consider them the first choice around a productive garden. They can drown beneficial beetles and other insects that wander in. Shelter traps are more selective and give you better information.
Protect seedlings while they outgrow the vulnerable stage
The most effective protection is temporary. Earwigs are far more likely to damage a seedling with two soft leaves than a plant that has established roots and tougher growth. A few days of protection can be enough.
Practical steps for the next seven days
- Check plants after dark with a flashlight for two nights in a row.
- Pull mulch back from seedlings and remove damp shelter nearby.
- Water in the morning rather than at dusk.
- Set two or three rolled-paper traps near the damaged area.
- Cover especially valuable seedlings with fine insect mesh supported so it does not press on the leaves.
- Replace badly damaged seedlings only after reducing the earwig shelter, or the replacement may be eaten too.
For container seedlings, raise pots off the ground with pot feet or a rack. Earwigs commonly hide beneath containers, then climb straight into the plant at night. A container sitting on a damp patio can support a surprising number of them.
When earwigs do not need to be controlled
Finding a few earwigs under mulch is not a reason to panic. In established beds, they often spend more time feeding on aphids and decaying matter than on healthy foliage. If your tomatoes, peppers, roses, and larger herbs have a few cosmetic nibbles but are growing well, leave the earwigs alone.
The line is simple: take action when seedlings are losing meaningful leaf area night after night, growth is stalling, or plants are being killed before they can establish. Do not treat a handful of ragged leaves on a vigorous mature plant as a crisis.
The non-obvious part is that a cleaner-looking garden is not always a healthier one. Earwigs thrive in excessive moisture and clutter right around seedlings, but a living garden still needs mulch, organic matter, and insect habitat elsewhere. Create a protected zone for young plants, trap the concentrated population, and let the rest of the garden keep its balance.
