possible tree fungus

Asked March 17, 2016, 11:44 PM EDT

We have a elm tree in our front yard that drops half of it's leaves every year after blooming. is there anything we can do to treat it/

Hennepin County Minnesota

1 Response

Dutch Elm Disease

The most common and serious disease affecting American elm trees is Dutch elm disease. It is caused by a fast-moving fungus called Ceratocystis ulmi, which infects the vascular system of the tree. The tree's access to nutrients and water is blocked. At first, only parts of the elm die, but in time the entire tree may be infected. A tree may die within a year of the first symptoms, or it may take several years. The first and most obvious symptom of infection is browning and wilting of the leaves, which often also drop prematurely from the tree. If your American elm is dropping wilted, brown leaves between a month and six weeks after they finished opening, it may be infected with this disease. Although you can remove infected parts of the tree, the tree may not recover, and the disease can spread to nearby trees. Keep it as healthy as possible to give it the best chance of survival. If the tree is severely infected, it will probably have to be removed.

Elm Leaf Beetles

Elm leaf beetles feed on the tender, juicy leaves of American and other elms. Usually, this does not pose a health threat to the tree, but severe infestations can be unsightly. The bugs chew on the leaves until they are ragged and torn. The affected leaves turn brown, die and may fall off the tree, although some may cling to the tree until fall. Because the larvae are usually deposited at the base of the tree, bands of insecticide, applied around the trunk at intervals of about a foot, can be effective at stopping the insect pests. As the larvae crawl over the bands, they pick up the poison and die.