Back in the office again now, so a couple of updates to the blog now. The first concerning the new pest contender – blackfly!


If the slugs weren’t enough, it’s looking like it might be a bad year for blackfly aphids (well, a good year for the blackfly, not so much for us). These sap-sucking pests can form huge colonies very quickly; like other aphids, they can reproduce asexually and very fast. Heavy infestations damage leaves and even beans themselves, and can lead to a build-up of mold as well as the sucking damage, because of all the unwanted honeydew that they release.

If you start seeing blackfly colonising your plants, you can do several things:

1) If there are not many, squash them. Bit grim, but a swift thumb and a bit of tissue paper will take care of light infestations. As will:

2) Wash the plants. Get a soft sponge thoroughly soaped up with e.g. fairy liquid or similar, and wash the blackfly off the plant. Gentle washing shouldn’t damage the plant, although try not to knock off any gone-over flowers, which are quite fragile. Rinse off with clean water.

3) If you’re getting repeated attacks, it might be time to remove the growing tip of the plant, which is the bit that they are most interested in. If you’ve had 8-10 bunches of flowers on your plant, you probably won’t be getting that many more, so if you take off the top two inches or so then not only will you reduce your risk of blackfly – but the plant can put its energy into fattening your beans.

Whatever you do, and especially if you do #3, please make sure that you do the same thing to all of your experimental plants.

I had also had suggestions from some volunteers that moving a few 'sacrificial' plants like nasturtiums near the beans can offer the blackfly an alternative target (from which you can then squash them as well), reducing the load on the beans.