Wisconsin experiences a wide range of winter storms, each with its own set of challenges for trees and landscapes. The five specific types of winter storms that threaten our trees are snow squalls, blizzards, ice storms, freezing rain, and sleet. While blizzards are commonly known for their destructive potential, it’s important to recognize that other types of winter storms can cause even more damage to trees.
The Internal Resilience of Trees
Externally, winter’s cold and snowy weather shows its effects on trees, but internally, trees possess remarkable adaptations that make them nearly impenetrable. In Wisconsin, we are known for our freezing temperatures. These temperatures expose trees to tough climate fluctuations over the course of a year. When the temperatures are below the freezing point, trees utilize special adaptations to handle these temps. Intercellular freezing is when a tree produces protein molecules that will allow for ice to crystallize in the spaces between the cells. When ice nucleates in those spaces, it allows for frozen water to begin attracting liquid water. Once this process occurs within trees during winter, they are capable of withstanding nearly any temperature.
In order for trees to set up for this “bulletproof” stage, they will undergo seasonal changes in autumn, preparing them to become dormant. The first stage occurs when trees begin losing their leaves. Once all the leaves have fallen off the tree, we can recognize that the tree has shut down its growth and cell division and is in turn, in a dormant state. The second stage requires the temperature to drop below freezing, telling the tree to begin to withstand low temperatures.
How Blizzard’s High Winds Affect Winter Trees
Blizzards are classified as any storm in which winds exceed 35 mph, the visibility is less than a fourth of a mile in all directions, and the duration of the storm is three or more hours.
With winds exceeding 35 mph, it’s no shock that blizzards have the potential to cause branches or even whole trees to break or be pushed over. Beyond this, blizzards have the potential to damage a series of trees in a neighborhood. The scale of these effects depend on the severity, duration, and the kinds of trees impacted by a blizzard’s forces.
Prior to a winter storm hitting, inspecting your property for trees that are more likely to fail will allow you to take action before these problems occur. One such preventive action is cabling and bracing trees, which reinforces the structure and ultimately the longevity of the tree.
Be sure to contact Wachtel Tree Science for consultation well before a winter storm occurs to identify potential concerns and to protect those trees you are worried about.
A Wisconsin Ice Storm Makes Driving Difficult, But Challenge Trees Too
Ice storms are judged by their duration, the wind exposure, and the amount of accumulation of ice on the tree.
It may be beautiful to look at all the individual branches of your tree sparkling with ice in the sunlight, but branches can be destined to break, split, or fall due to ice’s weight. Logically, we can understand that any part of a tree that isn’t structurally sound prior to a Wisconsin ice storm is likely to break after such a storm occurs. Decaying components, dead branches, or long and heavy branches are all sections of a tree that should be reinforced or addressed prior to winter’s arrival. The best way to protect your tree against ice storm damage is to contact a Certified Arborist.
Certified Arborists can assess a tree and its structural integrity in order to provide you with suggestions to protect your tree. Prior to winter, pruning can be a very effective way to improve a tree’s structure by taking out specific parts of a tree. Decaying, dead, poorly attached and tightly spaced branches can be targeted during pruning to avoid trees reaching the point of breaking during a winter storm. Similarly to blizzards, utilizing preventive measures like cabling and bracing will mitigate the effects of Wisconsin ice storms.
Snow Squall Damage to Trees
Common around the Great Lakes, snow squalls tend to be just as intense as blizzards but aren’t as long lasting. Recall that blizzards are storms that last three hours or longer, snow squalls are short bursts of intense wind, snow, and ice. These short bursts alone can force parts of a tree or entire trees to topple to the ground. To prevent winter damage to trees from snow squalls, bracing and cabling weaker trees is recommended to defend against strong wind, snow, and ice. If a tree’s structure is poor or a tree is not properly supported, it may fall unpredictably and unwantedly on power lines, homes, or cars.
Freezing Rain’s Beauty, Beauty & Danger
Freezing rain begins as snowflakes fall from the clouds, then passing through a layer of warm air on the way to the ground, turning to water. This liquid rain doesn’t have enough time to completely refreeze in the air as it falls, but will freeze when it lands on something less than 32 degrees Fahrenheit. Thus, freezing rain has virtually the same effect as ice storms when it comes to covering your trees.
Freezing rain covers trees weighing down branches and stems within a tree. This excess weight from ice can cause limbs to break. Sometimes this damage is so severe the remainder of the tree will need to be taken down due the extent of the damage. If the damage is less severe, the resulting wound on your tree will cause undue stress since a tree will need to react to damage to continue to protect itself from a now exposed part of the tree. Some wounds can be prone to disease insect issues. Wounds can also expose trees to decay and other stresses. Pruning your trees prior to a freezing rain event, will improve your trees and help to limit damage from occurring.
Sleet’s Impact on Your Trees
Much like freezing rain, sleet melts when it passes through a layer of warm air. However, sleet will refreeze when it passes through another layer of cold air. Sleet is known for its compact shape, which results in it bouncing off surfaces once it hits. Sleet can effect the bark of your trees due to its roughness. However, sleet is not likely to cause branches to break or fall since it does not build up on a tree.
It is good to know the type of winter storms we and our trees may encounter in the state of Wisconsin. The potential effects of a Wisconsin winter storm on your trees can never be fully determined, but there are preemptive measures you can take to protect your property this winter.
Contact a Wachtel Tree Science Certified Arborist for a consultation to learn how to prevent potential damage during the winter.
