Spider mite

Spider mites feed on plant leaves and needles throughout Western Washington, creating tiny white or yellow stippled spots that give foliage a mottled appearance. Heavy infestations progress to bronze or bleached foliage with entire leaves dropping; webbing may be visible on leaf undersides. Leaves feel gritty to the touch when colonies are present.

Monitor leaf undersides in dry periods when populations surge. Strong water spray dislodges mites; repeat every few days. Horticultural oil or soap with undersurface coverage suppresses populations. Avoid high-nitrogen fertilizers favoring mites. Conserve predatory insects.