How to keep caterpillars off my brassicas

After following your advice, I have a veg garden which was my pride and joy. However, my brussel sprouts, purple sprouting broccoli and cauliflowers are simply covered in caterpillars. There are green ones, and millions of ones who appear to be wearing a rather smart tweed.
I have tried picking them off, doing lots every day, but there are far, far too many. There are hundreds of clusters of little orange eggs on every leaf and clouds of cabbage white butterflies fill the air. When I picked some purple sprouting heads to cook, I washed them so carefully which took forever, but still found caterpillars on my plate which has put me off completely. There is something so unappetising about seeing a little dead body in my food. I don't like to kill any living thing.

Is there anything I can do to save the rest of my veg, or is it too late?

I thought that next year I would plant all my brassicas in a big fruit cage so the butterflies can't get to them. Is this the only solution? I planted calendula next to them (which are a luxuriant mass of orange), in the hope they would put off buterflies, which they obviously do not. Is there any other companion plant which does work?

I wondered if I should cut off all the leaves and hope they would re-grow when it is a bit colder and the butterflies might have gone. The stalks of the plants are very thick and the plants are about 2-3 ft high.

The purple sprouting is beginning to flower on a few stalks, so should I cut my losses, save some seed and start again?

Everything else is unbelievably successful, I never dreampt of such crops before reading your book. Thank you.


 I am glad your garden is doing well Larkspur and sorry about the caterpillars. Are you sure you can't squash a few rather than lose your plants? AND/OR it should be that after this rain, new growth will save the day - I have already noticed it happening here and we have been taking some well eaten and yellowing leaves off brassicas (to compost) which helps reduce slug numbers and to keep on top of weeds, which often hide under old leaves.

Funnily enough I have few caterpillars at present, on kale and sprouts. Some brassicas have been under mesh and they are certainly the cleanest, next year you could lay mesh on top as in the photo below, the cauliflower under it have grown really well, they are to curd in April.

 Cauliflower planted 1 July after garlic harvest - the uncovered plants were more attacked by insects

 same view 8 weeks later on 26 August

Re your sprouting, if it is purple sprouting for the spring it should not flower now, but you could try cutting off flowering stems and hope it changes its mind. Another year, try sowing it later, even in early June for planting early July eg after overwintered garlic or early lettuce.

By charles

Just to add I found fleece really good too. My cabbages are virtually hole free, and look amazing, especially when compared to the skeletal remains of the sprouts in the next row that I didn't cover!

By tess

The only thing uncovered was my Kale which is well grown and appeared not to have a problem with caterpillars that have turned neighbours crops to lace.

That is until today when the population of caterpillars appears to have exploded. That will teach me, but it is lovely to see the clouds of butterfly's.

By bluebell

Hi Larkspur,

I have found total success with Bacillus thuringiensis! This was the bacterium that made Louis Pasteur famous before he invented Pasteurisation. These blighters almost destroyed the Lyon silk industry until he discovered them killing the silkworm caterpillars and instituted simple hygeine to the rearing cages. I bought the spores in a carrier powder some years ago under the trade names on BioBT and Bactospeine w p. Both are a wettable powder of which I mix a small quantity in a bit of water in my sprayer and then top it up. The spray is effective against many caterpillar pests on Brassicae, Strawberries, Raspberries, Tomatoes, Cucumbers, Peppers and ornamentals (so the blurb says; I've only ever used it on Brassicae). The caterpillars have to ingest contaminated leaves after which they become moribund and die. Unlike chemical pesticides there is no residue in the plants and washing will remove any remaining bacteria (which don't affect humans anyway).Biobt can be bought from but I can't find an online supplier for bactospeine
Hope your brassicae survive and thrive; it's been a weird season. My second sowings are way ahead of the first because of the cold spring


By Willsandlands

It's not much help for this year's crops I know, but I have found enviromesh to be the answer. Last year I invested in some 5m wide meshes that come right down securely to the ground and give the plants room to grow, and this year for the first time ever, no insects in my caulis or calabrese at all so far, really clean veggies. Expensive, but long-lasting solution. We live very close to a butterfly reserve, and there are clouds of butterflies over the garden this year, many of them white, but they are not bothering me!

By wendyp