Residents of the Northeast enjoy a wonderful variety of tree species. Oaks, maples, elms and hickories create landscapes rich in color, diversity and sheer beauty.
Unfortunately, these trees are susceptible to disease. Various species of fungus are the primary cause of disease in Northeast trees. Typically, fungal diseases are slow growing which allows homeowner time to begin restorative treatments.
The following is a discussion of the five most common illness which affect trees within this region.
Leaves of hardwoods that exhibit dark blotches or dead patches can be indicators of leaf blight, or anthracnose disease. Anthracnose infection is due to a fungus which infiltrates the tree, causing the leaves to die.
At first the tree is able to fight the disease, but as more leaves die the tree weakens and eventually succumbs to the illness. Black walnut, white oak, dogwood and sycamore trees are most often infected by Anthracnose.
Armillaria Root Rot
This is another fungal-caused disease which affects both hardwoods and softwoods. Armillaria is a primary cause of the decline of oak species. The fungus weakens the tree, making it susceptible to attack by insects or other diseases.
Wounds on a tree increase the plant’s susceptibility to disease. Oak wilt is a fungus that moves from tree to tree through both infected roots and insects burrowing into wounds. Once infected, Oak wilt is fatal.
Dutch Elm Disease
Most homeowners have heard of Dutch elm disease. In infected trees, the vascular system becomes clogged with a fungus, restricting the movement of water.
Although American elm species are highly susceptible to this disease, European species also succumb.
Another fungus-caused disease, canker rot infects red oaks, hickory, honey locust and white oak trees. This rot kills both the strong, interior heartwood as well as the softer sapwood layers of the tree.
Diplodia blight causes extensive damage to urban trees. This fungus kills soft, new growth then progresses to killing major branches and finally the entire tree.
Blights are spread through the reproductive spores of the fungus. Airborne spores can travel long distances and thereby infect the trees within a neighborhood, park or windbreak.