Cutworms: protect newly planted seedlings

A seedling severed near soil level overnight may have been damaged by a cutworm. Confirm the pattern before treating: collapsing stems, chewing animals and mechanical damage need different responses.

Check the damage and the culprit

University extension guidance describes cutworms as caterpillars that can cut young plants at or near ground level and hide nearby. Inspect around a freshly damaged plant, especially at dusk. Photograph any caterpillar without assuming every soil larva is a cutworm. A pinched, rotten stem may indicate disease instead.

Protect a small planting

1. Remove damaged plants and record which rows are affected.
2. Use a simple smooth-sided collar around vulnerable seedlings, with its lower edge set into the soil and room for the stem to grow.
3. Check beneath and around collars so pests are not enclosed with the plant.
4. Inspect frequently during the vulnerable establishment period and remove collars when no longer needed.

Make protection workable

Cardboard can be useful for a short trial but may soften after irrigation. Reused plastic must be clean, free of sharp edges and collected afterwards. Do not leave a tight loop around an enlarging stem. Protection is only worthwhile if water can still reach the roots and daily inspection remains possible.

Record what changed

Compare protected seedlings with a small comparable area only if the likely loss is affordable. Count missing plants and note night-time damage. If losses continue, ask for identification before expanding treatment. Avoid scattering unlabelled poison or household substances where birds, children or poultry can reach them.

Namibian climate and microclimate

Warm conditions can change pest activity, while irrigation concentrates growth in small attractive patches. Collars may become hot in direct sun, so inspect plant contact and choose a light-coloured or shaded design where appropriate.