A
fungal disease of the
Elm tree that is believed to have actually come from the
Himalayas. It got its name when it was
classified by
Dutch scientists in 1917. In the 1930s, it made its way to
North America on an
infected crate, and has been responsible for the destruction of over half the Elm trees on the eastern part of this
continent. The
epidemic is still raging (these things move
slowly for trees), and is gradually heading west. DED is transmitted from tree to tree by the Elm Bark Beetle,
root grafts (when two
elms touch
roots, kind of an
arboreal STD), and by infected tools.
Symptoms of Dutch Elm disease begin with a sudden wilting in the upper leaves of the tree. As the wilting spreads, the leaves turn from green to yellow, and then to brown, then they die. If this happens during the autumn, it will seem normal, but next spring, the new leaves will be smaller than normal, and the tree will be dead by midsummer. Discoloration of the wood is another symptom, and can be checked by peeling back the bark on a wilted branch, and checking for streaking.
If you or a loved one has Dutch Elm Disease, there are a variety of treatments available. If the infection has just started to take hold, then quickly pruning the affected branches ten feet below the discolored area can stop the spread. Make sure you do not do this between April and July, however, because this is when Bark Beetles are the most active. Fungicide is another effective way to combat early infestations, but it is ineffective against advanced stages, or if the tree has contracted the disease through root graft. You can even give your tree drugs to stimulate its natural immune system that will fight the fungus.
To prevent Dutch Elm Disease, make sure that you give your tree a regular inspection to make sure that it shows none of the warning signs given above. Clearing away dead wood, banding the tree, and applying insecticide will keep away bark beetles that might spread the disease. Do not buy firewood made of elm, as it may be contaminated. Or, you can give your tree drugs to keep its immune system up.
Thanks to www.elmcare.com, which seemed pretty hot on trying to get me to give drugs to trees.