Oak Wilt is a fungal vascular disease that affects all kinds of Oak trees. The disease can be fatal. The trees most at risk are Red, Pin, Hill’s, Black and Scarlet Oaks.
What is Oak Wilt
Oak Wilt, caused by a fungus (Bretziella fagacearum), is spread underground through root grafts or above ground by sap beetles.
The fungus clogs the trees vessels, stopping the flow of water in the tree, causing die off.
It can cause death in as little as weeks in Red Oaks, while other Oaks can survive two to five years
Sap beetles are attracted to the spore mats and spread the sap to other trees.
What are the symptoms of Oak Wilt?
– The first sign is usually rapidly browning and dying leaves at the top of the tree.
– Presence of Sap Beetles
– Dying limbs
– Fungal mats under bark. These spore mats cause ruptures and splits in trunks.
– Streaking in the outer sap wood of branches
How is Oak Wilt treated?
– Infected Oaks can not be saved but the spread to other trees can be limited with removal of trees and separation of roots between trees
– Trunk injections to improve health of trees
– Trenching around infected trees
– Avoiding heavy or unnecessary pruning of susceptible Oaks during beetle flight season which is generally April-August.
– Nutritional treatments to improve plant resistance to disease
– Removal of infected wood