This has been a devastating year for our American elms in Ladd's Addition, as indicated by the Elms Update to the left.  Losing even one of these trees is a difficult site to see, making this year's losses especially apparent.
 
In an effort to stop the spread of Dutch elm disease (DED) in the impacted areas, SOE inoculated five trees using a more complex and expensive macro infusion process (as compared to our standard annual inoculation process).  Using pumps and large tanks, these trees were injected with Arbortect fungicide.  The cost for this operation was over $1,800 using volunteer labor and in-kind support from Davey-Organicare (arborists) and equipment loans from the City of Portland.

Over the coming months, the SOE board will be evaluating the future direction of our DED prevention programs.  Although the inoculation processes and products we use are the latest and most effective available, new strategies may be evaluated.  We will seek community input as we develop alternatives.  Future newsletters will have more information about our choices.

 

Dutch elm disease is a fungus that invades the vascular system of the American elm (analogous to the veins of animals) and prohibits water movement in the tree. If the vascular system is not effectively carrying water and nutrients, leaves begin to wilt and eventually the elm dies. While inside the tree, the fungus produces microscopic spores that play a role in propagating the disease.
 
DED is spread in three ways: by bark beetles which carry the DED spores on their bodies, by the interaction of diseased tree roots with healthy tree roots, and by not disinfecting pruning and cutting tools previously used on a diseased tree.  You can learn more about DED at the SOE website and here.
 
There is no cure for DED, but effective treatments to slow its progression have been on the market for many years and are actively used by SOE to protect the trees in Ladd's Addition.