Flies on Holly Bushes
My Holly bushes seem to attract the common house fly. They don't seem to do any damage but they congregate in large numbers on the bushes. Have you ever heard of this? Is there anything I should be doing to prevent this?
Certified GKH Gardening Expert
Flies are normally attracted to the honeydew left behind from pests, like aphids. I would treat the shrub with neem oil, as this is effective against most pests (especially aphids) but is perfectly safe for beneficial insects, animals and birds (as well as you). Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm