Cabbage white caterpillars
Green or yellow-and-black caterpillars eat large holes in cabbages, kale and sprouts, sometimes down to the veins. Yellow eggs sit under the leaves, singly or in clusters.
Large and small cabbage white butterflies lay their eggs on brassicas from May to September.
What can you do?
- Check under the leaves weekly and squash or wipe off the yellow eggs.
- Pick the caterpillars off by hand.
- Cover the brassicas with insect mesh from planting, well secured at the edges.
- For a heavy attack, spray with a product based on Bacillus thuringiensis, which only affects caterpillars.
Prevention
Keep brassicas covered with insect mesh all summer. Parasitic wasps and birds clear up many caterpillars if you don’t use poison.
When to watch out: May–September