Root diseases are often deadly to trees. These types of diseases can be difficult to diagnose and manage because the cause of disease lies beneath the soil. Two types of root rot that can affect pine trees in particular are: Armillaria root rot and Phytophthora root rot.
Armillaria root rot is a fungal disease that can affect all types of conifer trees. One of the most common signs of root rot is a white fungal growth under the bark of the infected tree or mushrooms growing at the base of the tree or stump. The fungus that causes armillaria root rot can spread from an infected root of a decaying stump to affect trees in the surrounding landscape.
Pytophthora root rot is also caused by a fungus and finds its host in true fir, spruce, pine, and Douglas-fir trees. This type of root rot is often associated with poor drainage issues in surrounding soil. Young trees are more vulnerable to this disease than older trees and are often killed from the infection.
Above ground, it is noticeable that a tree affected by Pytophthora root rot is declining, but symptoms are similar to many other diseases. Diseased trees present with yellow or undersized needles, wilt, branch dieback, and premature needle drop. While above-ground symptoms may not distinguish the disease, when a cut is made into the root-crown area of the tree, a characteristic cinnamon brown color can be observed.
To prevent root rot diseases, avoid planting in poorly drained soil and remove symptomatic trees to prevent spread of the disease to new hosts. Consult a licensed arborist like Eric’s Tree Service to implement proactive planting practices to help promote longevity of your landscape and limit future disease.