How to Care for Trees During Winter

It’s doubtful that anyone would be surprised to know that deciduous (leafy) and coniferous trees react differently from each other during the cold winter months. One can easily identify that by appearance. But can you identify how trees prepare themselves, and how we might help them prepare, for the dropping temperatures?

Whether it’s working on holiday shopping or gathering nuts for the winter, living and breathing creatures are preparing for what winter brings. That goes for trees as well. As late fall turns to early winter, trees begin to enter a state called “dormancy.” This means that they temporarily stop their growth and development.

Why does a tree lose its leaves?

During dormancy, a tree has no use for its leaves because of the energy shortage it is experiencing. Abscisic acid, which slows down a tree’s protein production, is produced and interrupts the growth of both deciduous and coniferous trees.  For deciduous trees, however, it also collects where the leaf’s stem connects to the tree which results in the leaf falling off.

This process can be evaded if a tree is kept indoors where temperatures and light patterns can remain steady.  However, this can be harmful to the lifespan of a tree, so this option is not ideal. If the dormancy process worries you, don’t fret: it’s part of a very natural cycle in a tree’s life.

What are the benefits of tree bark protection?

Bark protects a tree from physical and environmental damage, but what protects the bark? While bark increases its cold tolerance throughout the tree’s life, frost crack can occur. Even though the air temperature during winter could be below freezing, the direct sun temperature could be much warmer. When a tree’s bark is exposed to these conflicting temperatures, frost cracks can form. If water—snow, for example—gets into the cracks, the tree’s tissue can freeze rapidly. When this occurs, ice crystals form in the cells of the tissue which cause the cells to burst. This kills the tissue and causes harm to the tree’s overall health.

If your trees are exposed to direct sunlight during the winter, particularly trees with thin bark, it’s recommended that you provide shade for the trunk. This may sound complicated, but the solution is as simple as purchasing a solar barrier or burlap covering. It’s a small investment for the health of your trees—which provide many benefits, year round.

Even though harsh winter conditions are to be expected, we never know what the weather is going to do in this day and age. As you may be aware, this is due to a global climate change. Learn more about the global climate change and its effect on Minnesota.