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by Steve Castrogiovanni

We have heard for years of the impending doom of the white, green and black ash that are native to the mid-Atlantic area, due to the Emerald Ash Borer. In the last year, this ominous prediction has come true. This can be seen in places like Clara Barton Parkway along the Potomac River, which has always been green and lush. It now has dead tree canopies littered throughout the tree line.

Sadly, ash are being killed in staggering numbers by this pest. What people aren’t taking in to account is how quickly these trees are becoming a threat to the public. Dr. John Ball from South Dakota State University says “Moisture contents go from 80% on a recently infested tree to less than 40% on one standing dead.  The girdling by the insect causing the roots to decline, hence water uptake is reduce but there is also some drying of localized sapwood independent from the roots dying.  Essentially the trees become brittle and fall sooner than expected. ”

Trees being attacked by Emerald Ash Borer do have distinctive signs.

  1. D shaped exit holes
  2. Discoloration of the bark
  3. Epicormic growth from the base (sucker growth)

Image 1. (Left) D Shaped exit holes (Center) Discolored bark from birds feeding on borers (right) Epicormic growth on canopy interior

It is important to have an arborist inspect your ash trees to determine if they are infested. Mead Tree & Turf Care, Inc. offers preventative treatments if your ash tree is not currently infested. A declining ash does not always mean Emerald Ash Borer. The Banded Ash Clear Wing attacks ash trees that are under stress and will also leave exit holes which are large and circular. The Emerald Ash Borer attack ash trees regardless of their health.