Elm trees are large trees with gray bark and leaves and berries that attract a variety of wildlife. Elms grow quickly and quite tall – if infection doesn't kill the tree before that can happen. Tree diseases have cut down the world's population of this noble tree.
If you have an elm or elms in your yard, there are a few notable diseases to look for and keep ahead of so that the tree remains healthy.
Dutch Elm Disease
Dutch elm disease is spread to trees by beetles. The disease can spread quickly throughout the trees and clog the systems by which the tree absorbs water. Dutch elm disease is likely to kill a tree that is infected, but older trees that are heartier might be able to survive for a time after the initial infection.
The primary symptoms of Dutch elm disease are the leaves turning yellow, then brown, then falling off when it isn't the right season for shedding. Once symptoms start to show, call in a tree pruning service immediately to cut off infected branches and perhaps stop the infection from spreading throughout the tree.
If you have several elms and only one is infected, treat your entire yard for beetles and have a tree removal service take away the infected tree so that the others don't suffer a similar fate.
The fungus causing verticillium wilt starts in the soil and moves up into the elm tree through its roots. You might not see any initial differences on the bark, but the leaves will begin to lighten, wilt, then fall off the tree. By that time, this contagious plant disease may have run amok in other areas of your hard.
Keeping your tree and soil well fertilized and watered can help the tree spring back if the verticillium wilt has not taken too great of a hold yet. But if the problem is left untreated to the point that the leaves are raining off the tree, there might not be any treatment options left to save the tree. You will need to call in a tree removal service to ensure the tree is safely and completely removed so that the disease can't spread elsewhere in your yard.
Sooty mold is another elm disease that can take hold in the surrounding soil, but in this case the problem is mostly that the disease creates a gross looking black coating on the tree's leaves. The coating can spread out to any sidewalks nearby or fall down on people under the tree during strong winds.
Honeydew-excreting insects that can live on and in the elm tree attract the fungus causing sooty mold. Treat the tree for the insect infection, and the sooty mold should clear up eventually. You, your landscaper, or a tree trimming service like Arbor Man Tree Care can cut away any blackened leaves in the meantime.