We are losing 5 -10 holly plants per year - have a lot of them in an arc. We have stopped replacing them due to cost. The bark of the plant at the base shows signs of damage. The question is who is doing it. I took the plant to a garden center and they said it looked like vole damage. I took their word for that for a couple of years.But this spring I looked more carefully at one of the dead plants and it seems that the damage is more like some kind of insect infestation. Some of the bark is eaten away and some seems to be undermined by something tunneling below the exterior of the bark.
Has anyone experienced this kind of problem? And if so, what could be a solution?