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 graft
s (when two elms
, 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.