Ice storms cost millions of dollars of damage in the United States every year, and the Midwest and East Coast states tend to come off worst. An ice storm occurs when more than a quarter of an inch of freezing rain collects on surfaces after a warm front moves in during otherwise cold weather. Trees are particularly susceptible to storm damage, as the weight of the frozen water becomes too much for the plant's structure to cope with. Learn more about the effects of an ice storm on your trees, and the steps you should take to avoid problems.
How ice storms damage trees
The ice that accumulates during a storm can increase the weight of a tree by more than 30 times. Different trees and species react differently to this immense pressure. If a tree already has weak, dead or dying branches, it is likely to suffer more significant damage than a healthy, strong specimen.
Certain species of tree are also susceptible to damage. For example, brittle or weak tree species can suffer extensive problems during an ice storm. Elms, true poplars, birches and willows cannot cope with the added weight of all that frozen water. Unfortunately, many homeowners choose these trees because they grow quickly and offer immediate shade.
Experts recommend that homeowners in areas prone to ice storms choose trees that can withstand the damage. Species like the sycamore, yellow birch and white ash are stronger than the most susceptible trees, but for very resilient species, choose oaks, larches, and cedars.
Pruning trees can increase their resilience to ice storm damage. It's better to prune trees during the winter, as the tree is dormant. The main aim is to make sure the tree has a robust limb structure.
Limbs and branches to remove include:
- Crossing branches that can rub together and cause damage
- Vertical twigs, which are often weak
- Small twigs, which create more surface area for freezing ice
It's sometimes necessary to remove a whole branch, particularly if the limb could fall on your property or on power lines. In most cases, this isn't a job the average homeowner can do safely, so it's important to call a professional tree service to do this work for you.
If you do decide to remove a whole branch, you need to take care. Where the branch joins the trunk (or a larger branch) you will see a ridge of tissue, called the branch collar. The collar produces hormones that help the tree heal naturally. As such, you should never cut off the collar, as the tree may become more susceptible to disease. Cut at an angle that allows water to drain from the site and avoid using a synthetic 'sealer', as this will slow the tree's natural healing ability.
Dealing with storm damage
Even pruned trees are susceptible to damage during a severe ice storm. In the aftermath of a storm, homeowners must often decide what to do with damaged trees.
Generally speaking, you should remove a tree if:
- The plant has completely uprooted
- There is complete trunk failure
- More than half the branches are broken
In these cases, the tree's structural integrity is beyond repair, and the plant is a potential hazard. In other cases, you can probably save the tree with careful pruning and repair. That aside, it's worth asking an arborist for more advice. He or she can inspect the damage and recommend the right course of action. For example, an arborist can assess how quickly the tree will recover and the likelihood of future problems with decay and fungal infection.
When pruning damaged trees, it's important to consider the plant's future structural integrity. Cut branches in a way that encourages a balanced crown to grow. Some wounds can cause discoloration and decay of trunk tissue, so you may need to check the tree on an ongoing basis to assess recovery.
Ice can sometimes cause damage that's difficult to see. Cracks can form parallel to a branch and will run to the point of attachment. It's important to look carefully for these damaged limbs, as they are likely to fall and could cause damage or injury. Bent trees will often return to their normal form some time after the storm. If the bend occurred in the bottom third of the three, you may notice future structural problems, but you can stake small bent trees upright while they grow.
Ice storms cause millions of dollars of damage every year. With the right preventive care and post-storm treatment, you can prevent some of the problems these trees can cause. Contact a professional tree service to discover more about pruning and removing damaged trees.