How to Manage Pests
Pests in Gardens and Landscapes
Trees infected with Phytophthora spp. may decline over a period of years before eventually dying or
they may be killed in a single season. Slow decline occurs when the roots are attacked; rapid decline
occurs when the crown or basal stem is attacked and girdled in a single season.
If bark tissue is carefully cut away, reddish brown streaks or zones can be seen in the inner bark and
outer layer of wood. No fungus mycelium is visible in the tissue affected by Phytophthora, distinguishing
this disease from Armillaria root rot.
wood of a Phytophthora infection