Q: Shortly after we had these pavers installed we noticed a small gray patch of something. It slowly grew to a large gray patch. Now we have a second gray patch. And the first patch has developed little white flies. Any idea what we might have here? Note: the little white things that look like lint are alive. They move under their power and appear to go airborne when the wind blows.

A: Ah ha!

If the white things are alive, my guess is that they are aphids of some sort. This is borne out by the black covering on the mondo leaves…it’s sooty mold growing on the honeydew secreted by the aphids still above the two spots feeding on the tree leaves.

You can control aphids with any garden insecticide (click for sources).