Hypoxylon Canker

Hypoxylon Canker is a destructive fungal disease that affects a wide range of tree species. The following information is based off of what Texas A&M has published. “This pathogen primarily targets hardwood trees, particularly oaks and hickories, but can also infest conifers in some cases. Hypoxylon Canker typically infects trees that are weakened or stressed due to factors such as drought, root damage, or poor tree health. This starts as a symbiotic relationship, until one part of the tree starts to die, even if it's just a branch. This will give the Hypoxylon Canker signals that its host is dying which then makes this fungal disease turn parasitic, and that harms the tree.”

To identify this condition, one should observe certain key characteristics. As the fungus develops, small sections of bark will slough from the trunk and branches, then collect at the base of the tree. Where the bark has sloughed off tan, olive green, or reddish-brown powdery spores can be seen. Different tree species that are infected with Hypoxylon Canker will produce the different colors of spores. These cankers usually start as red or purple spots which gradually darken. The bark around the cankers may appear rough or cracked. Examine the branches and twigs for the presence of black, pimple-like structures known as perithecia. These small structures release spores and can be seen on the surface of the cankers. Take note of any wilting or discoloration of leaves, which may indicate that the disease is spreading.

Unfortunately, once symptoms of Hypoxylon Canker begin to manifest, it is too late for any form of treatment. The disease progresses rapidly, affecting the inner tissues and compromising the structural integrity of the tree. Despite the advances in tree care and disease management, scientists have not yet developed a reliable treatment for this insidious pathogen.

Trees that have died from Hypoxylon Canker and are located in an area where they could be a hazard, should be removed as soon as possible. During removal, it is very dangerous to climb trees killed by Hypoxylon Canker as the fungus decays the wood so rapidly, the tree may not support the weight of a climber. Instead, hire a company that will use bucket trucks or other mechanical lift devices and always make sure to hire companies with insurance for tree removal.

If you need help identifying Hypoxylon Canker, Arbor Source Tree Experts can assist. We will take all of the worry out of keeping your trees and shrubs healthy and beautiful year round. Visit us at www.ArborSource.net to request a visit from our ISA Certified Arborist or call (832) 671-0331. 

Example of Hypoxylon Canker

In this example this is when it starts releasing the reddish-brown, powdery spores