American linden trees (Tilia americana) are loved by homeowners for their lovely shape, deep foliage and beautiful fragrance. A deciduous tree, it thrives in U.S. Department of Agriculture plant hardiness zones 3 through 8. Unfortunately, this attractive tree is susceptible to multiple diseases. Some of the linden tree diseases can impact a tree’s appearance or vigor. For a rundown of the diseases of linden trees and other linden tree problems, read on.
Leaf Spot Linden Tree Problems
Leaf spots are common diseases of linden trees. You can recognize these linden tree diseases by circular or splotchy spots on the leaves. They grow larger and merge over time. These leaves fall prematurely.
Leaf spot diseases of linden trees can be caused by many different fungi. These include an anthracnose fungus and the leaf spot fungus Cercospora microsera. Sick linden trees weaken because photosynthesis is interrupted. In order to deal with leaf spot, prune out infected twigs when the trees are dormant. Also, rake up fallen leaves and destroy them.
Verticillium Wilt on Lindens
If you have a sick linden tree, your tree might have verticillium wilt, which is one of the most common linden tree diseases. This is also a fungal disease that starts in the soil. It enters the tree through root wounds.
The fungus enters the tree’s xylem, infects the branches, and spreads to the leaves. The symptoms of a sick linden tree with this disease include leaves dropping prematurely. Unfortunately, treatment of this disease is nearly impossible.
Canker Linden Tree Problems
If you see sunken areas of dead tissue on your linden tree trunk or branches, it may have another of the most common linden tree problems – canker. The dead spots are usually caused by fungi. If your sick linden tree has cankers, prune off the affected branches as soon as you notice the damage. Prune well below the bottom of each canker into healthy tissue.
If cankers appear on a tree’s trunk, it is not possible to eliminate the canker. Give the tree top care in order to prolong its life.
Other Diseases of Linden Trees
Powdery mildew is another common issue with lindens, and easily recognizable by the white powdery substance that covers leaves and even shoots. New growth can be distorted. The best thing to do is to plant the tree where it gets lots of sunlight and the air can circulate. Don’t give the tree a lot of nitrogen either.