By Dennis Tompkins
Does “wind sailing” really help reduce the risk of tree or branch failures in our tall evergreen trees?
Some tree service companies promote the idea that removal of branches throughout a tree’s canopy will reduce wind resistance and make a tree safer. This may seem logical to a homeowner since fewer branches would appear to allow strong winds to pass through a tree canopy, reduce the number of branches susceptible to breakage and prevent the tree from swaying so much during severe storms.
While such a treatment may appear to make sense, many certified arborists raise a number of questions about the practice.
First, there is no scientific evidence that wind sailing makes a tree safer. There are thousands of trees in residential areas that have never been wind sailed that have survived severe storms for decades. The tiny percentage of trees that do fall and expose an uplifted root mass likely suffered from a root-rot disease.
Keep in mind that Mother Nature allows trees to grow to adapt to their surroundings. While mankind has altered many of the natural environments, trees generally still have the ability to survive the increased exposure to the elements resulting from removal of neighboring trees.
However, there are numerous examples – like clearing for a development – that demonstrate the potential impact of leaving a few scattered trees that are no longer protected by their decades-long neighbors. Such a drastic change in a tree’s surrounding environment can result in stress and ultimately cause tree failure.
Some studies have demonstrated that the outside limbs actually buffer trees by deflecting the winds around the canopy. This enables branches to protect each other and the trunk. Aggressive branch removal, however, can expose the remaining limbs to strong gusts and consequently make some of them more vulnerable to breakage.
Needles, twigs and branches are the food manufacturing plant for a tree. The combination of excessive thinning by wind sailing, the resulting reduced food supply and the increased demands for energy to respond to the wounds may stress a tree and impact its long-term health and safety.
Tree topping should also be avoided “to make a tree safer.” Generally, conifer trees will attempt to form new tops by causing upper limbs to eventually grow upward. This often creates multiple tops. Such new tops are poorly attached to the trunk and are more susceptible to future breakage than trees with their original structural integrity intact. Plus, topped trees are just plain ugly.
There are circumstances where limited branch removal may be justified. These include dead limbs, large branches that overhang valuable targets and branches damaged by a severe wind storm or an ice and snow event.
The key to a proper approach to a tree of concern is to employ a knowledgeable and responsible tree service or certified arborist who understands how trees respond to such treatment.
I do not practice or recommend wind sailing. However, if a homeowner is truly worried about a tree, a hazard assessment may be prudent. The investment would be worthwhile if it provides a sense of peace of mind by either determining that no action is recommended or that a problem should be addressed.
Our conifer trees naturally shed some of the more vulnerable limbs during storms but, other than creating messes in our yards, they generally cause little damage. This would seem to be a small price to pay for the wonderful forest ambiance that many residents enjoy.
Dennis Tompkins, a Bonney Lake resident, is an ISA certified arborist and ISA qualified tree risk assessor. He provides small tree pruning, pest diagnosis, hazard tree evaluations, tree appraisals and other services for homeowners. Contact him at 253-863-7469 or email at firstname.lastname@example.org. Website: evergreen-arborist.com.