somewhat unique aphid problem

Asked March 19, 2016, 1:01 PM EDT

Hi. I have a southern-facing window with lots of sunlight, and I've been successful in growing leafy greens and even radishes all year indoors. Recently, however, I've developed an aphid problem. With no natural predator indoors, they keep coming back. First I tried hand-controlling them every day, then using oil and mint sprays, and then changing the dirt completely. But still they return. They are particularly devastating on seedlings. Thus, with all my larger plants harvested, I'm at a standstill. Whatever I try to grow dies a few days after sprouting because of the aphids. I think I introduced the aphids via my indoor worm farm. I thought I was providing my plants beneficial worm castings and leachate. Then one day I noticed aphids in the leachate. I don't see aphids in the worm farm, just the leachate. So, here's my two-part question: 1. Do you think it is possible to introduce and reintroduce aphids via a worm farm? Please keep in mind that I feed the worms only food scraps and paper, no garden waste. I'm thinking that, unlike compost, the worm farm doesn't get hot enough to kill aphids. Yet what are the aphids eating in the worm farm, I wonder. 2. If aphids are in the farm, is it safe for my plants to microwave the leachate and castings, let them cool, and then use them? I'd be killing biologics in the castings, but I assume nutrients would remain intact. Thank you as always.

Montgomery County Maryland

1 Response

It is highly unlikely that aphids are being introduced to your plants from a genesis in the vermicompost leachate. Aphids lay their eggs (or give live birth) on living plant material where there is sugary sap flowing for the youngsters to feed on.
If aphids are found in the worm farm or the leachate, they were probably attracted to the plant material in the food portion of the 'farm', where they probably died and wound up in the leachate.
Although you have tried controlling the aphids on the living plants, we recommend that you redouble your efforts.
Do not microwave the leachate and castings. You will destroy the microbes that are such an important part of the finished product.
LS