You might not believe this, but it is true: sunlight can damage trees. Just like how people get sunburns, trees get sunscald. However, sunscald is not temporary like sunburns. Sunscald can cause premature decline or permanent damage to trees. You should know that once damage has occurred in a tree, there is no way to repair it.

What causes sunscald?

Mostly it is sudden temperature changes that can lead to damage to trees, but many other factors also play a role in causing sunscald.

Certain trees are more susceptible to sunscald than others, and they include spruce, ash, balsam fir, linden, maple, birch, douglas fir and eastern white pine.

Young tree barks are also more susceptible than older barks. Older barks are thicker, therefore, providing better insulation for cells in the trees.

The south side of trees is usually accustomed to intense sun. If you move a tree from the tree nursery and turn it 180 degrees, you will be making the sensitive north side face south, thus making the tree more susceptible to sunscald.

What tree types are most affected by sunscald?

Fruits

Sun scalds mostly affect plants such as berries, grapes, and apples. Excess pruning or disease may take away too many of the protective shades. The fruits are left exposed making them susceptible to sunscald. It also affects crops such as peppers and tomatoes.

Young trees

Younger trees are often affected during late winter or fall when the weather changes are rapid. Warm days make the cells open up, while during the cold nights the cells shut.

Photo of a person whitewashing a fruit tree by hand, to prevent sunscald.

Fruit tree being whitewashed. The white paint helps prevent sunscald by protecting the tree’s bark from overheating in the sun.

What can I do to prevent sunscald

You can protect your young trees by placing them where they can get enough shade during afternoons. You should also ensure that you give them the correct amount of fertilizer and water. Make sure to be careful when pruning vines and branches.

Seasoned fruit growers often paint the trunks of young trees to protect them, this practice is commonly referred to as whitewashing. This is an effective method of sunscald prevention; however as the young tree grow you may find the oddly painted white trunk to be unsightly.  An alternative option would be to wrap the trunks of your young trees, using either plastic or paper, to keep the bark from becoming too hot.

For more information or an Affordable tree health evaluation call 813-407-9974 and speak with a Tree Medics arborist today!