I have large redtip photinias that are losing their leaves and dying. There is something on the ground around the trunks that resembles red sawdust. We have a number of these plants (10) and the others are doing well. The plants are trimmed and I could not find signs of the fungus on the leaves. What could this be? There looks to be some small bore holes along the trunk. Any suggestions?
Certified GKH Gardening Expert
It sounds like it has a borer of some kind. Flathead borers are the most common on this plant. This article will help: http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/INVERT/flatheaded.html