Oak Wilt or Scorch?
We have two large oak trees in our front yard, one red oak and one white oak. Both were planted in 1999 via tree spade. The red oak leaves are browning prematurely this year and beginning to drop, the white oak leaves are not. We are concerned that the red oak may have "Oak Wilt" disease. Please advise. Thanks
Montgomery County Maryland
We looked at your photos. The browning on the red oak leaves may be due to environmental issues and bacterial leaf scorch.
Oak wilt has been found in western MD. But we have not seen it in the eastern area of the state.
There are multiple factors that can contribute to decline of oak trees. When subject to drought, poor soils, poor drainage, etc. they can be susceptible to insect and disease problems. These issues put the trees under severe stress and can result in root loss.
Here is an article on Why Oak Trees Are Declining http://extension.umd.edu/hgic/topics/why-oak-trees-are-declining
Unfortunately, Bacterial leaf scorch has become more of a problem in recent years.
Generally the disease process lasts 8-10 years, and there is no cure.
Pruning out dead wood and diseased branches is recommended. Here is our page on bacterial leaf scorch. https://extension.umd.edu/hgic/bacterial-leaf-scorch-trees
Lastly, You may want to contact several certified arborists for an onsite diagnosis regarding the health of the trees http://www.treesaregood.org/