The name sounds like something terrorists would use, but anthracnose is actually a disease that strikes oak trees.
Paula Flynn, a plant pathologist at the Iowa State University Extension, says anthracnose is becoming a common problem for many Iowa homeowners this year. Flynn says anthracnose is caused by a fungus and the name may sound alarming but it’s a fairly minor problem that only causes leaf spots or blotches.
She says there are many reports of the oak tree disease across the state this spring and summer, but she says concerned homeowners can relax — a bit. Once you see the spots on the leaves, there’s nothing you can do as it’s already infected the tree. The leaves may curl up and fall off but it rarely becomes widespread enough to kill the tree. She says spraying a fungicide likely won’t do any good once the tree’s infected.
Anthracnose can also strike other broadleaf trees, including ash, maple, sycamore and walnut — but for all of them, it’s relatively minor. However, Flynn says another disease that can afflict oak trees -can- be fatal to the tree, and it’s something to watch for closely. Signs of oak wilt include brown or grey leaves that fall off and dying branches. Unlike anthracnose, the disease oak wilt gets into the water conducting tubes of oak trees and can kill the trees, especially red oaks and pin oaks.
Oak trees can be protected against oak wilt with an injection if there’s concern about other trees with it nearby, but once a tree gets it, it’s likely going to be dead, perhaps within a few weeks. For more information, visit www.isuplantdiseaseclinic.org.
Related web sites:
ISU plant disease clinic