If you have trees around your home and worry about a fall, one factor to consider is the direction and intensity with which the wind typically blows through your property. If you have been living on a property for many years, you may already know its unique weather patterns. However, if you are new to a property, it is worth taking time to think through before developing a removal or pruning plan.
You can measure the wind direction and speed with simple devices like wind socks or weather vanes or go high tech with digital anemometers and other gadgets. Check out your local prevailing wind data online which graphs direction and speed of winds over many years.
Think about whether your trees are protected on the larger landscape by hills, groups of trees and/or buildings, or are they fully exposed and stand alone on a flat landscape. If there are buffers, have they long been there or have there been recent site changes such as construction or land clearing?
Trees slowly adapt over many years to the site on which they are growing by sensing where additional strength is needed and adjusting height, branching, allocating root and wood growth in order to stand upright against wind forces. Sudden, strong changes in wind direction (like from a storm) or an abrupt change in exposure can drive a tree to the point of breaking or uprooting.
Have you ever come outside and seen a branch laying on the ground or perhaps heard a loud crack and fall? A branch can crack and break anytime wind, snow, ice or just gravity puts more pressure on it than it can handle. Branches grow to withstand a certain amount of these forces but they also can develop weak spots, called defects, around which they can break easier than normal. Holes, clustered branches, inclusions, and cankers caused by infection are some examples of weak areas in a tree.
A branch can also break on a hot, dry day due to a moisture imbalance within the wood which causes the wood fibers to separate. This is called “summer branch drop” and it’s still not fully understood by tree experts.
Lastly, wood strength varies greatly by species. For example, White Pines are naturally more prone to breaking under high storm winds than Oaks. And certain trees are prone to developing defects such as the Bradford Pear which develops multiple branches originating from one spot on the trunk.
If you have a tree that has a break or crack and it is concerning to you, it’s best to have an arborist check it out in a Hazard Inspection.