Posted: Wednesday 2 May 2012
by Pippa Greenwood
Conditions here have been so windy and wet that it amazes me how any pest can hold on firmly enough to be able to attack my plants.
The recent bad weather prompted me to make hot, warming meals, and my home-grown purple sprouting broccoli was the perfect accompaniment.
But yesterday I was met with a miserable sight. Clustered around the most inaccessible parts of each broccoli stem were small clumps of mealy cabbage aphid. On the whole, my brassicas remain free from pests, as my dislike of caterpillars in my food is so great that I grow the plants in micromesh-covered frames. Not only do these frames protect my crops from caterpillars, but aphids and pigeons are kept away too.
Well, usually. Recently I unzipped the covers, which must have been when these little greyish-white aphids snuck in, and started to breed.
Conditions here have been so windy and wet that it amazes me how any pest held on firmly enough to attack my plants. Perhaps the micromesh covers created a welcoming shelter for them.
Once on the plant and breeding, it’s amazing how fast their numbers build up, and soon their sap-feeding activities can cause noticeable leaf yellowing on plants. Shoot tips may also become distorted and, if you leave the infestation too long, the plants may even be killed.
One of the stranger symptoms of dead shoots is that you can end up with extra side-shoots and multi-headed plants. This may sound like a good thing, but the quality and overall crop is severely diminished.
So, I've just spent a happy half hour treating the clumps of mealy aphid with an organic fatty-acid based spray. I just can’t have the aphids breeding and spreading, as my summer cropping brassicas are nearly ready be planted out!