“Sun scald? But it’s winter!”
How can trees get damage from a sun if it’s not even as intense as it is in the summer? Believe it or not, sun damage is a very real risk in the winter time. Trees go into a dormant state when the weather gets cold. And since trees don’t have calendars, the only way they know it’s not winter is when it gets warm. It’s pretty easy to fool a tree that spring has arrived.
What typically causes sun scald is a change in the tree bark’s temperature. This fluctuation can occur on a particularly warm winter day, or if the sun is reflecting off the snow and onto the tree. The warmed tissue comes out of its dormant state to prepare for spring, only to be hit with freezing temperatures once night falls. Unprepared, the active bark cells die, making it difficult for the rest of the tree to attain water and leaving a large scar on the tree. Other side effects may include:
- Bark cracking or breaking off the tree
- Insect or other pest problems
- Tree disease
Damage may not appear until the following warm seasons, when the tree begins growing again.
Which Trees are at Risk?
The level of risk your trees are at can be determined by their age, how recently the tree’s physical presence has been modified, and its species. Young trees, especially those that have thin bark or have been recently planted, are at the highest risk of sun scald. This is because the bark is still not thick enough to withstand strong and sudden changes in temperature.
Old trees that have been pruned also need extra winter tree care. If lower branches have previously been accustomed to the shade of upper branches, this new exposure makes them susceptible to sun scald. For much of the same reasons, trees that have been replanted from shady to sunny areas are also at risk and will require additional winter tree care before the cold weather hits.
In addition to young trees and recently altered trees, these tree types are particularly susceptible to sun scalding due to their perpetually thin exteriors:
- Honey locust
- Sugar maple
- Fruit trees
If you are unsure whether your tree is at risk of sun scald, call a Hansen’s certified arborist for the best advice available to you!
What to Do: Preventing Sun Scald with Winter Tree Care
There are several ways you can protect your trees from sun scald, all of which revolve around maintaining the same temperature around your tree by blocking or reflecting the sunlight away from the bark.
Depending on your aesthetic taste, you can wrap or paint your tree. By wrapping trees with commercial wrap, you insulate the tree and set up a barrier against the sunlight. However, you must remove the wrap when the seasons change to avoid girdling the trunk and attracting insects or diseases. Painting your tree trunks with a white latex paint can also reflect enough sunlight to prevent sun scald.
As always, one of the best ways to prevent any damage from your tree is by planting the correct tree species for a certain area and practicing good tree care habits Also, by watering your tree regularly and by mulching the root zone, your tree will be better prepared for cold weather. For more information concerning sun scald prevention and other winter tree care, contact Hansen’s today!