Note There have been very few beech samples sent into the OSU Plant Clinic. One nursery sample had a Phoma leaf spot diagnosis and there was a diagnosis of Phytophthora and another of Phomopsis. Mature trees in the landscape have been noted to decline in droughty or low soil moisture conditions. Overall, beech diseases are not an important issue in the PNW. The disease known as Beech Leaf Disease, caused by a foliar nematode Litylenchus crenatae ssp. mccannii, found in eastern North America has not been found in the PNW. Beech Leaf Disease symptoms include characteristic banding patterns on the leaves as well as thickening leaves that eventually shrivel and fall off the tree prematurely.
References Zhao, Y., Bonello, P. and Liu, D. 2023. Mapping the Environmental Risk of Beech Leaf Disease in the Northeastern United States. Plant Disease, 107:3575-3584.