I went to the community garden plot this evening to water and took a few moments to walk around looking at peoples’ plots. Outside of some powdery mildew on one of the pumpkins in the large patch the owner of Electric City Conservatory planted this summer, everything looked good. That is until I noticed a friend’s Brussels sprouts. I thought they were wilting in the heat because the leaves curled under and the plant looked kind of sickly. I took a closer look at the leaves, and was horrified to see the masses of aphids all over the bottom of them. Then I went to the Brusselss sprouts next to my plot that will go to Meals On Wheels. They have them, too. It looks like we have a case of mealy cabbage aphids.

Mealy Cabbage Aphids

Mealy cabbage aphids (Brevicoryne brassicae) often attack members of the Brassica family. They’re larger aphids (as aphids go anyways) that are gray in color and appear in large groups. They have waxy covering, too. This helps them repel water, not that they’re going to be drenched hiding out underneath the leaves.

Supposedly they won’t kill plants at this stage of the summer, but they can transmit turnip and cauliflower mosaic virus. Plus, with heavy feeding I’m sure it doesn’t help sprout production.

Good Riddance

To get rid of them this summer, I’ll break out the insecticidal soap and will have to carefully go through the leaves to make sure I thoroughly cover the patches of the aphids. I’ll rinse them the next day, squishing any stragglers to make sure they’re gone. And at the end of the year, we’ll have to be sure to remove the plants because the aphids can overwinter in stems.

How to Prevent Mealy Cabbage Aphids

I’ve never had a problem with aphids on my Brussels sprouts. Next year if I plant them in the community garden I’m going to try to remember to plant a little white clover underneath them. I’ll seed it when I plant the sprouts. (Which is pretty early in the season). And instead of pulling it out as it grows, I’ll just use the clippers to keep it trimmed back so it doesn’t outcompete with the vegetables. This should also help retain moisture. This has been a huge issue this summer in this particular garden since the soil is rather sandy.

At the end of the season, I’ll dig it under. It’s disappointing to find the mealy cabbage aphids on the otherwise beautiful plants. At least they can be taken care of without much of a problem and I know how to be proactive to deter them next year.