Cabbage white caterpillars

Cabbage white caterpillars

Learn how to protect your brassica crops and nasturtiums from caterpillars of cabbage white butterflies.

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Time to act
Time to act

Do not Time to act in January

Do not Time to act in February

Do Time to act in March

Do Time to act in April

Do Time to act in May

Do Time to act in June

Do Time to act in July

Do Time to act in August

Do Time to act in September

Do Time to act in October

Do Time to act in November

Do not Time to act in December

Cabbage white butterflies are the caterpillars of both the small and large white butterflies (Pieris rapae and Pieris brassicae). Small white caterpillars are pale green with a body up to 2.5cm long, while large white caterpillars are 4cm and are yellow with black markings. The adult butterflies lay eggs from May to June and then July to September. This means you can find cabbage white caterpillars on your brassicas from late spring through to autumn.

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Symptoms

Caterpillars eating holes in the outer and inner leaves of brassicas, with nasturtiums also being used.

Find it on

Brassicas and nasturtiums

Organic

Cover plants with horticultural fleece or fine netting to prevent butterflies reaching the leaves. Check plants regularly and pick off any caterpillars that do make it through. Grow nasturtiums as a sacrificial crop and move eggs and caterpillars from your brassicas to the nasturtium leaves. Spray young caterpillars as they hatch with the biological control Steinernema carpcapse.

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Chemical

With heavy infestations, use an insecticide based on pyrethrum (only use once a season on crops).