Written by: August Hoppe, President Hoppe Tree Service, Certified Arborist WI-0477A
Summer is thunderstorm season in Wisconsin, despite our dry conditions lately. You never know when the weather will change here, and in a small amount of time a storm can cause a lot of damage to our trees and property. Many homeowners are concerned with big trees near their homes and afraid of potential damage if the tree were to fail so close to the house. However, just because a tree is large does not mean it’s a threat.
There are significant patterns to storm damage that we see time and time again.
Here is a list of common patterns we see:
Weak-wooded species - Fast growing, weaker wooded trees are more prone to failure. This includes willow, box elder, and silver maple.
Dying or declining trees - Stressed trees that are showing significant signs of decline such as thin canopies, lack of leaves and large sections of deadwood are weaker trees. Root systems in trees like this are compromised as well, with less root ability to anchor the tree in the ground. Decay is present in trees like this and can create weak points that fail in storms. Failure could be a branch breaking or even a tree toppling over due to root decay. Removal of hazardous weak or dead trees that pose a risk to property or people prior to a storm is always a good idea!
Excessive weight or lean - Tree tend to be stronger when they have a more upright growth habit. When limbs head out horizontally, they can accumulate excessive weight, making them more likely to break in a storm. Shortening the length of a limb or outright removal of a limb can mitigate the risk and make a tree stronger. In general, trees with lean pose more of a risk.
After big storms, we often receive a burst of calls from our clients reporting unfortunate damage. Some of this damage could potentially have been avoided with tree care prior to the storm. Our certified sales arborists can help identify and mitigate these at-risk trees and branches with annual inspections. While the weak structural integrity of these trees may go unnoticed to the untrained eye under normal conditions, excessive weather can quickly turn these at-risk trees into serious hazards.
The Importance of Pruning Cycles
Following a proper pruning cycle is one way to reduce the risk of failures. Every year trees put on new growth that extends further away from the branch-to-trunk connection. This puts excessive weight on the tips of the branches. Weight reduction pruning is great for large trees that have overextended branches. By reducing the weight on the ends of these branches, it is less likely that these branches will reach their breaking point. A proper weight reduction pruning will cut back to a strong lateral branch that will leave the tree healthy and looking natural.
A proper structural pruning can also help prevent failures. Removing diseased, damaged, decaying, deformed and dying branches within the tree's canopy will great improve the tree's ability to withstand wind, snow and ice storms. Most larger trees perform better and are stronger when they grow with a single central leader to the tree.
However, often we find that trees are growing with two or even three competing leaders that are all the same size. These multi-leader trees are more prone to splitting and failing in storms. When we prune, removing or reducing the size and height of competing limbs will encourage the growth of a strong central stem. Depending on the tree species and structure, we suggest a healthy maintenance pruning every three to five years.
Many of the failures that occur are due to a tree's poor structural integrity. With older mature trees, they may look healthy and vigorous, but the limb and branch structure itself may be heavily compromised. The size and age of the tree may not allow for pruning for better structure. In this case, we often install tree support systems to help strengthen the tree.
Co-dominant stems are just one example. Over time, as these stems grow together, decay can set in at their junction point and become a point of structural weakness. While the risk cannot be eliminated, properly installed metal support cables can greatly reduce the risk of co-dominant stem failures. These static cables help support the co-dominant stems at the union and reduce the loads on these stems.
Your Hoppe sales arborist can inspect your trees and recommend a proper pruning approach. To schedule a visit by one of Hoppe’s certified arborists to your yard, contact us today at 414.257.2111 or Request a Quote.