With their jagged, ovular leaves and coarse bark, elm trees are a sight to behold. The elm first appeared in Asia more about 40 million years ago, and later moved to North America. Today, however, Elms in North America are threatened by a disease known as Dutch elm disease. If you are lucky enough to have an elm tree on your property, it's important to know a bit about preventing, detecting, and handling this serious tree disease.
How is Dutch elm disease spread, and how can you protect your tree?
Dutch elm disease, like many tree diseases, is caused by a fungus. Fungus on an infected tree produces spores that are found in the tree's inner bark. Beetles that feed on this bark, known as elm bark beetles, pick up the spores, and when the move to another elm tree, then bring the spores along with them, infecting the new tree.
If you want to protect your tree from Dutch elm disease, the key is to minimize contact with the beetles that carry the fungus. This can be accomplished by:
- Never bringing any firewood or dead wood onto your property. (It may contain the elm bark beetles.)
- Cleaning up fallen leaves and twigs regularly throughout the fall. (These may attract the beetles).
- Having insecticides applied to the lower branches of the tree in the fall when the beetles are most active.
What are the signs of Dutch elm disease?
Even if you take all of the precautions above to protect your tree, there's still a chance it could develop Dutch elm disease. The first sign of the disease is usually certain branches turning brown and dying. The leaves will turn yellow and then brown. Additional branches will succumb to the same plight over a period of several months or years.
If you suspect your tree may have Dutch elm disease, take a close look at the fallen leaves. Are they uniformly brown by the time they fall? If they're only yellow with bits of brown along the margin, the problem is probably elm yellows, a less serious fungal infection. Contact a tree care specialist who can come treat your tree with fungicides and hopefully clear up the infection. If the leaves are completely brown, you most likely are dealing with Dutch elm disease.
What do you do if your tree has Dutch elm disease?
Sadly, there's no saving the tree. To prevent spreading the infection to other trees in the area, it's best to have it removed sooner rather than later. If you take down the tree yourself, be sure to burn the bark to destroy any elm bark beetles it is harboring. Inner wood can be salvaged and used if it is still in good shape since the beetles are not typically found here. For further assistance, contact local professionals, such as those from Arbor Man Tree Care.