Cabbage white caterpillars

by Jane Moore

My recent rant about this year's plague of slugs obviously touched a raw nerve with the allotmenteers of Britain.

Cabbage white caterpillarMy recent rant about this year's plague of slugs obviously touched a raw nerve with British allotmenteers. I'm clearly not alone in feeling ground down by the enormity of the problem.

Now, as if to confirm that nature is gaining the upper hand on my plot, the cabbage white caterpillars have joined in. A number of my calabrese plants are barely alive, having been stripped down to the leaf ribs; they're crawling with the (admittedly rather pretty) yellow and black stripy caterpillars of the large cabbage white butterfly. These are easily confused with the smaller, bright green (and far less attractive) caterpillars of the small cabbage butterfly. I have those too.

It's been a rotten year for butterflies, except the cabbage whites, which seem to have flourished. What can be done about them? Several allotmenteers I know simply pluck the caterpillars off by hand, grinding them underfoot as they go. This method requires a certain ruthlessness I seem to lack - I'm getting more squeamish as I get older. And I do have a girlie passion for butterflies - even the cabbage whites are lovely to see fluttering about the garden.

There are organic sprays available and also a biological control, which I really must try next year. My current method of control is somewhat cruder, but less barbaric than that of my fellow plotters: I too pluck the caterpillars off, but I gather them up in a bucket and tip the whole lot out on a path. This provides a feast for the birds, and the caterpillars at least have a chance of escaping and living a happy and fulfilled life as a butterfly - even if it does spell more problems for my brassicas in the future.

Discuss this blog post

Talkback: Cabbage white caterpillars
Your comment will appear after a quick registration step

Gardeners' World Web User 12/09/2008 at 12:24

If you are vigilant you can spot the clusters of yellow eggs on the leaves; squashing them is more humane and less messy!

Gardeners' World Web User 12/09/2008 at 20:20

I have to cast doubt on your method, the cabbage whites are foul tasting to birds both as caterpillars and butterflies. There is a theory that the Brimstone which is the first butterfly to herald spring survives because the birds mistake it for the foul tasting cabbage whites! If there are brassicas or even radishes near the path then the larger caterpillars will crawl back on to them and continue their life cycle.

I had to resort to 'deris plus' which gave me a break from caterpillar picking and also sorted the whitefly. A fine mesh is the only certain answer however on the allotments many plotholders just leave there crops to be consumed thus exacerbating the problem by allowing the cabbage white populations to increase. The same goes for potato blight if people just leave the haulms to propagate spores. Gardeners should look after their crops or compost them?

Gardeners' World Web User 14/09/2008 at 10:33

We love to see the the caterpillars and get round the problem by having a patch of nasturtiums in the corner which both cabbage whites love and we dislike. All butterflies need a helping hand.

Gardeners' World Web User 14/09/2008 at 19:28

I know exactly how you feel - I've had brassicas stripped to skeletons on numerous occasions. But not this year! - I grew them in a raised bed and fixed a butterfly-proof net around them - just like the bird protection for my straw, and it worked! I've been keeping a close eye on the plants and so far have found just five caterpillars (Heaven knows how they got in!). So this year it's home-grown sprouts for Christmas, for the first time in years.

The reason I found this blog was that I was Googling for information about when the Cabbage White butterfly stops laying eggs - i.e. when can I remove my netting?! - the plants are trying to burst out! Can anyone advise?

Gardeners' World Web User 17/09/2008 at 10:05

Thanks to all the above!! I took on my allotment last year and seem to have only produced broccoli to feed the caterpillars :-( Although I started the season with nets over all the brassicas the broccoli grew too tall and found such a pain every time I wanted to weed. I WILL definitely be keeping netting on next year and am going to try tying canes along the long edge of the nets as a weight and to ease access when i need to open the bed up for weeding. As I am one of the girlies that can not yet pluck up the courage to pick through them, I am Hopeful there is still plenty of other ideas for not spraying.

See more comments...