Oak wilt is a destructive, tree-killing disease. It destroys oaks like how Dutch elm disease damages elms. The bacteria get into the water-conducting vessels of the sapwood through roots connecting diseased and healthy trees or through fresh wounds.

When the mold is in the vessels, nearby cells form balloon-shaped structures that spread to the infested vessels and clog them. This disturbs the sap flow in the vessels as well as the foliage wilts and falls. The disease is a menace to all oaks. However, trees of the red oak group are destroyed swifter than trees of the white oak group. Little can be done to help infested red oaks. Remedies are available to aid infected white oaks and lessen the threat of infection to noninfected oaks situated near the infected trees.


White Oak Symptoms

Orchard Park Tree What is Oak Wilt

Oak wilt causing leaves to turn brown and fall

Symptoms in white oaks are very different than in red oaks. Symptoms could grow in the upper crowns of white oaks, but they do not spread as quickly. Symptoms are often limited to one or a few branches.  

Trees in the white oak group are rarely killed entirely as trees in the red oak group. Leaf discoloration happens, but the changes are usually slower than with the red oak group. Staining of sapwood under the bark of infected branches is not usual on white oaks. Spore mats don’t develop on the white oaks.

It is vital to remember that oak wilt is typically confused with root issues, drought, construction stress, or borers. To get an authentic assessment, schedule a tree inspection with an experienced Orchard Park arborist.


Red Oak Symptoms

Early foliar symptoms are shedding, wilting, and bronzing of the leaves at the ends of limbs in the upper crown. The symptoms can develop through the top quite quickly, usually within a few weeks.

Bronzing starts at the outer leaf edges and travels toward the midrib. The area between the green and discolored areas is typically not distinct. The leaves wilt along with the discoloration. Both entirely and discolored green leaves fall from the tree in vast numbers. Though, a few discolored leaves always stay on the tree.