A tree disease near Boerne

This week, my mother had several Spanish oaks (Quercus texana) cut down because they were infected with hypoxylon canker (Hypoxylon sp.). She sent photos of the fungus.

According to the Texas Plant Disease Handbook, hypoxylon canker spreads through spores, which enter through injured areas on limbs or the trunk. "Trees which have been damaged by excessive fill soil are often attacked by this organism," states the handbook. "It is also suspected to be a fungus that can invade on oak wilt-infected trees. Control is achieved by maintaining the trees in a healthy condition. Avoid injury to the trunk and limbs and never apply fill soil around the trees. Chemical treatments would not be effective because the fungus is located within the tree."

According to Texas AgriLife Extension Service's East Texas Gardening, "hypoxylon canker has been noted in the death of many oaks in the East Texas area over the last several years. This disease is not rare, but due to the stressful droughts of the last several summers, a large number of trees are being affected." 

The Texas Forest Service has more information on hypoxylon canker, too. So does AgriLife Extension.

Mom told me that surviving trees nearby were fertilized, and now she's giving the trees soaking drinks of water for several weeks. Hope they survive!