Between the recent windstorm, a missed call on a hazard evaluation involving a Corliss logging operation and a devastating insect attacking Enumclaw landscapes, it has been an interesting week.
The Windstorm
It was not the biggest storm and tree failures may have been greater had the ground been saturated from recent rains. Some trees snapped off along their trunks and the usual debris from fallen branches and needles covered our yards.
Such storms cause some homeowners to unnecessarily cut down a tree. It is understandable to be concerned about a tree that fell and caused damage. However, the assumption that nearby trees will also fall may be false.
Ideally, the cause of a tree failure should be investigated before deciding to remove additional trees. If a root disease contributed to a tree falling, then it may be prudent to remove neighboring trees. Generally, a qualified professional or knowledgeable tree service should help to make such an assessment.
For families that enjoy their trees, the investment would be worthwhile. It may provide comfort that other trees appear to be healthy and strong and should be retained. Unfortunately, some doorbell “arborists” and others with limited knowledge may have their pocketbooks more in mind than safety when recommending tree removals.
The Corliss Logging and a Missed Call
A few hundred acres of property were recently logged close to Bonney Lake. The removal of the forest cover exposed trees on surrounding private property to elements never before experienced.
Before the windstorm I received two requests for hazard evaluations of trees that bordered the logged area. When making such assessments, the primary concern is the location of potential manmade targets and the condition of suspect trees.
I was able to check nearby fresh-cut stumps in the logged area for signs of root diseases or decay. None was visible, but one cannot inspect the roots for such evidence. I recommended removal of one large Douglas fir and noted others with multiple tops to be watched.
The large fir trees on the one property survived the winds. However, several alders that did not threaten structures blew over. Their root systems were not very large so they were unable to withstand the winds.
On another property, I recommended a double trunk tree on the edge of the logged area to be removed. Another much larger fir tree that concerned me was somewhat isolated and potentially could strike a residence. Because of its good health and lack of visible defects, I recommended its retention, but that it be watched carefully during high winds.
The double trunk tree survived the windstorm, but the large fir did not. Fortunately, it missed the house. Upon close inspection of the root wad, it appeared to be quite healthy. However, decay was discovered in a few roots on the side that the winds struck. Apparently there was just enough decay present during a wind gust that the roots could no longer anchor the tree.
The roots were 5 feet deep directly under the tree, but became more shallow as they extended from the trunk. The roots stopped growing downward as they hit a layer of clay where water would accumulate and discourage further root penetration.
These incidences demonstrate that even a trained eye has its limitations and indicates sometimes the difficulty of evaluating hazards when viewing only the above ground parts of a healthy appearing tree.
Enumclaw under Siege
I noticed several fir trees whose branches had taken on a twisted and distorted appearance. They included large and several smaller alpine or subalpine fir trees that are highly susceptible to the balsam woolly adelgid. This insect is particularly serious on these trees and should be controlled.
When new growth begins in a few days, the tiny adelgid crawlers hatch, migrate to the new foliage and begin to feed. They inject a toxin into the wood that causes swellings, “gouts” and a bird claw appearance of twigs. Such attacks may eventually kill some trees.
Badly distorted trees should be removed. Small trees that are not grossly misshapen can be sprayed, but control is difficult. Insecticides containing the active ingredient Imidacloprid can be effective when applied in late April through early May when the crawlers are susceptible.
