mature red oak tree suddenly is dead

Asked August 1, 2017, 1:04 PM EDT

Why did our beautiful mature oak tree (40-50 feet) turn from green to brown? It's dead! We looked at a small leaf branchlet and saw what looked like some type of leaf miner on a couple of leaves but there were no trails that are typical with a leaf minder. This small branch of leaves has a brown mold at its segments and some of the leaves have a light hairy substance on the undersides. July has been a very wet month (14 inches of rain) with high humidity. Are other oaks dying in Maryland, or southeastern PA? Is there a tree expert that can look at our trees? Do we need to dispose of this tree by burning it? Should it be removed immediately or do we wait until January or February in order that the fungus does not spread? There are no mushrooms close to the base of the trunk. We have many different types of oaks on our 25 acres property. How do we protect our other trees?

Cecil County Maryland

1 Response

There are several things that contribute to decline in oaks. They are especially more stressed in urban environments (pollution, heat, compaction) and in droughty conditions. They also just decline from old age. It is hard to say for sure what brought your tree down. It was most likely a combination of stressors. When tree health is in decline, secondary problems (pathogens, insects) can come in. Hypoxylon and armellaria are two diseases in oaks.

We recommend that you contact a certified arborist if you are interested in having other trees checked for decline issues. Arborists can conduct an evaluation on site to check for disease symptoms, pests, or other problems -- and they can make recommendation for how best to care for the trees you have. You can find a certified arborist near you using the following website:

You can take the tree down at any time. You don't need need to wait until January - February to take it down, and you don't need to burn it.