We are growing blueberries in containers. We have covered the soil with a...
We are growing blueberries in containers. We have covered the soil with a layer of pine bark mulch, and have mixed some of the bark in the soil. Today I noticed there are a lot of small flies (see the attached photo) crawling all over the mulch. They do not seem to be on the bushes themselves. Are the flies a problem, and do we need to treat the mulch or bushes to get rid of them?
I think they are fungus gnats growing on the organic matter in your potting media. They do not pose a risk to the blueberries as they generally feed decaying organic matter not living plants. Drenching the whole pot with enough insecticide to kill the larvae seems extreme.
Allowing the media to dry out some will help control the pest but you need to mange the water in the pot carefully so the blueberries do not become drought stressed.