I have a number of mature Holly bushes that have done well in past years, producing flowers and then red berries. I fertilize with Miracid from Miracle Gro. This year the leaves on bushes in 2 apart locations started to turn brown and fall off. I thought it was some mites and sprayed with Volick Oil.
Most of the leaves are now off. I thought it might be vole, but no. What could be the cause and remedy?