Healthy elm trees' leaves turn yellow and tumble to the ground in late September to early November, depending on where you live. If they're turning yellow or brown and falling to the ground in the spring or summer, something is wrong. There are two diseases which commonly cause this symptom in elm trees: Dutch elm disease and elm yellows. Here's how to determine which one is affecting your tree, so you can treat it properly.
Dutch Elm Disease
A fungal infection that was brought to North America from Europe in the 1930s, Dutch elm disease has killed thousands of trees in American forests. Trees that lose their leaves due to Dutch elm disease generally lose them branch by branch. The leaves first turn yellow, and then they become brown and crinkly before falling to the ground. Often, trees will go from looking perfectly healthy to having several barren branches in a matter of weeks.
If it is caught early, Dutch elm disease is sometimes treatable. An experienced arborist may prune out the affected branches and spray your tree heavily with insecticide, hoping that it recovers. However, many trees succumb to the infection and wither away within a few years, with or without treatment.
If you have other elm trees on your property that are not yet showing signs of Dutch elm disease, spraying them with fungicide may help protect them.
Elm yellows is another dangerous fungal infection that affects elm trees. Its symptoms are similar, but instead of losing leaves one branch at a time, trees with elm yellows lose leaves across their entire crown. The leaves also turn yellow, but never become brown and crinkly.
Trees with elm yellows cannot be saved. In fact, if you find out your tree has this disease, you should have it removed immediately, as this will help prevent other nearby trees from becoming infected. It is important that the stump of the tree is also removed, as the inner tissues of the tree may harbor the fungus that causes the disease.
If you have elm trees on your property that are still healthy, having them sprayed with insecticides may protect them from elm yellows. The disease is spread from tree to tree by insects known as leaf-hoppers, and insecticides help keep the leaf-hoppers away.
Early leaf loss in an elm tree is never a good sign, since both Dutch elm disease and elm yellows are usually deadly. Contact a tree care expert, like R. L. Elliott Enterprises, Inc., in your area immediately if you think your tree has one of these conditions, since early action may save other trees, if not the infected one.