Absolutely the best way to avoid caterpillars from chomping through your brassica crops is to regularly check for eggs over the next few weeks. Even if they are growing under netting, it is wise to check the leaves for eggs (and caterpillars) two or three times a week if you can – they have been a little later to become active this year, but we’ve seen plenty of them flitting around lately and their activity is likely to continue well into September or October.
Which plants to check:
- Kale – Cavolo Nero, Curly Kale & Red Russian Kale
- Broccoli – Purple Sprouting & Green Calabrese
- Cauliflower
- Romanesco
- Cabbage – Red Cabbage, White Cabbage, Savoy Cabbage, Spring Greens
- Turnip & Swede
- Brussels Sprouts
Where to check:
- Underside of leaves
- In the nook between stem and leaf
- In the cabbage heart
- On new florets that might be forming
What to look for:
- Clusters of eggs – these could be pale green, dark green or yellow
- Individual eggs – these are usually white or yellow
- Caterpillars
- Holes in leaves
What to do:
- Wipe off eggs with kitchen paper
- Remove caterpillars carefully – pop them in a bucket and redistribute them to another part of the garden.
- Pop an insect mesh net over brassica plants to prevent butterflies from getting to them to lay their eggs.
When it comes to harvesting:
If you’re worried about caterpillars in your broccoli harvest, or any other brassica harvest, then you can soak the harvested crops in lukewarm water with a splash of white vinegar for a few minutes – any caterpillars will float to the surface. Then you can remove them, rinse your brassicas and cook them as normal!