â ModerateCutworms Cutting Down Young Bell Pepper Seedlings
Commonly affects: Capsicum annuum, Grossum Group (Bell Pepper)
Young transplants are found severed at or just below the soil line, sometimes toppled completely overnight, with the stem chewed through.
The short answer
Seedlings cut cleanly off at soil level overnight, with the toppled plant left lying beside the stump, are the work of cutworms. They are moth caterpillars that shelter in the soil by day and feed at night. Dig a few centimetres around the stump and you will usually find a fat grey caterpillar that curls into a C when touched. A cardboard collar around each stem prevents it entirely.
Confirm it before you treat it
- 1Look at the cut. Cutworm damage is a clean severing at or just below soil level, as though snipped â not chewed or torn.
- 2Check whether the plant was eaten. Cutworms typically fell the seedling and leave it, which distinguishes them from slugs and browsing animals.
- 3Dig around the stump. Scrape a few centimetres of soil within a hand's width and look for a fat greyish-brown caterpillar curled into a C.
- 4Go out after dark with a torch. Cutworms feed at night and are visible on the surface then, which is the most direct confirmation.
- 5Note the pattern. Losses of one or two plants per night, often in a line along a row, are characteristic.
Potential Causes
- 1Cutworm larvae feeding at the soil surface at night, most damaging to young, tender transplants
- 2Soil recently disturbed or freshly planted providing easy access for cutworms already present
- 3More common early in the season when transplants are small and vulnerable
Solution Steps
- 1Place a physical barrier (a cardboard or plastic collar) around each transplant stem, pushed a couple of centimetres into the soil, to block cutworm access
- 2Hand-search the soil around a damaged plant at night with a torch, since cutworms are usually nearby just below the surface
- 3Till or disturb the soil surface before planting to expose and reduce existing cutworm populations
- 4Replace severely damaged young transplants, since cutworm-severed seedlings rarely recover
What else looks like this
| Could be | How to tell it apart |
|---|---|
| Slug damage | Ragged chewed leaves and slime trails, with the plant still rooted. Cutworms fell the plant and rarely eat the leaves. |
| Damping off | The stem thins, darkens and collapses at soil level rather than being cleanly cut. The seedling is still attached. |
| Wind damage | The stem is broken and frayed, and several plants go at once during a windy spell. |
| Birds or animals | Plants pulled out with roots exposed and soil disturbed, rather than cut at ground level. |
| Stem borer | An entry hole with frass and wilting above it, but the plant remains standing. |
Recovery timeline
- Night 1Go out after dark with a torch and hand-pick what you find. This alone often removes most of the local population.
- Day 1Fit collars â a cardboard tube or a cut plastic bottle pushed a few centimetres into the soil around each stem, standing a few centimetres above it.
- Days 1â3Dig around any recently lost plants and remove the caterpillars you find near the stumps.
- Week 1Losses should stop. Collared plants are protected regardless of how many caterpillars remain in the soil.
- Weeks 2â4Once stems have thickened and woodied, cutworms can no longer cut them and the collars can come off.
If you do nothing
Losses continue night after night. A single cutworm can take one seedling per night for weeks, and a modest population clears an entire row of transplants before the plants are old enough to resist. Because each loss is a whole plant rather than damaged foliage, this is one of the fastest ways to lose a crop at the transplant stage â and by the time the pattern is recognised, the replanting window may have closed for the season.
Common mistakes
- Blaming slugs and putting down slug pellets. Cutworms are unaffected, and the losses continue while the cause goes unaddressed.
- Spraying the foliage. The caterpillars are in the soil by day and at the stem base by night; foliar sprays never contact them.
- Replanting into the same spot without a collar. The caterpillar is still there and takes the replacement the following night.
- Fitting collars only at soil level. They need to be pushed a few centimetres INTO the soil, or the caterpillar simply goes underneath.
- Not looking at night. A ten-minute torch inspection is the most effective single action, and almost nobody does it.
Prevention Tip
A simple cardboard collar around each transplant stem is a cheap, highly effective, purely physical prevention against cutworm damage.
Questions people actually ask
- What exactly is a cutworm?
- The soil-dwelling caterpillar of several night-flying moths. It is not a worm and it is not related to the pests that damage roots.
- How do collars work?
- They form a physical barrier the caterpillar cannot cross to reach the stem. Push a cardboard tube or cut bottle a few centimetres into the soil around each seedling.
- Do they affect mature plants?
- Rarely. Once stems thicken and toughen, the caterpillars cannot sever them, so this is essentially a seedling and transplant problem.
- Is there a biological control?
- Beneficial nematodes applied to moist soil are effective against the soil-dwelling stage and are a reasonable option for a repeat problem.
- Why do they cut the plant and not eat it?
- They feed at the base and on the fallen stem. Felling the plant is a side effect of feeding at soil level, which is why the seedling is left lying there.
