Turn away now if you’re squeamish about garden pests… our broccoli-growing adventure continues with the summer-long battle against the cabbage white butterfly. Friends warned us about the damage they can do to brassicas, of which broccoli is one. Did we put protective netting around our plants? No. But we will next year!
I basically made it a daily task to inspect the huge broccoli leaves for signs of butterfly. As half a dozen butterflies fluttered around the plants at the height of July & August, I was valiantly picking off caterpillars, scraping off eggs and even managed to knock away a couple of butterflies. I’ve turned into a butterfly killer! What’s happening to me??
Did it make a difference? Well, possibly… but the leaves still got eaten pretty badly. I wondered if I’d managed to thwart a tenth of the beasts. At one point I asked the question on a ‘grow your own’ forum “Is this worth it – will we end up with any kind of harvest or should I give up and pull them all up now?” The thought of fighting the pests for another six months was kind of dispiriting. But the answer came back, “don’t give up”. I was advised to thin out the plants (they were growing so vigorously and thick I wasn’t able to even get in amongst them to inspect all the leaves) and to net them over the winter to guard against being eaten by pigeons. The caterpillars will soon be over, I was told. You’ll still get a harvest come the Spring. So, I cut four of the ten plants down, at the base, leaving the roots so as not to disturb the others. They were so strong and fine I felt bad about it – a couple of the plants are over four feet tall. But the remaining plants do have more space now.
As regards the Cabbage White butterflies, I’ve learned there are two varieties – the small and large. The Large Cabbage White lays its eggs on the underside of the leaves, in batches altogether, and they’re yellow so easy to spot. They then hatch into speckly brown caterpillars. The small variety lays eggs singly, and they’re much harder to see. The larva (caterpillar) is green and smooth and blends in with the leaf colour. Before I knew this, I couldn’t work out why I saw so few of the speckly chaps, and so many of the green ones. Then I realised it was because I was much better at spotting and scraping off the eggs of the Large Cabbage White, whereas the singly-laid eggs were slipping under my radar and many more were hatching.
Anyway, the daily squishing of caterpillars isn’t altogether pleasant. I think if we grow brassicas again I will net them very securely!