How Do Trees Handle The Cold Of Winter?

As winter arrives, the soil is gradually freezing around the roots of your trees. How do trees handle the cold of winter? Do the frosty temps harm them?

Roots can be harmed by cold temperatures. Certified arborists have concluded that roots are more likely to be damaged by cold temperatures than the above ground parts of a tree. But the soil doesn't get so cold, and its temperature doesn't vary as much as the air. Cold harms trees by turning water to ice in the cells, creating crystals that can harm them.

Cold Weather Climates and Trees

Trees in cold winter climates have evolved to endure winter by being dormant. This means not just dropping leaves and stopping or slowing growth, but also lessening the amount of water in root tissues and branches. The reduced concentration of water in a plant's tissue works as a natural antifreeze. It takes deep cold to create ice inside them.

The water in the soil near the roots could freeze. However, the cold won't damage the roots until the water inside their tissues begins to freeze.

Sometimes that can occur, particularly in a long spell of harsh weather when cold has lots of time to penetrate from the air low into the soil. Frozen at 30 degrees isn’t the same as frozen at 0 degrees. Some trees begin displaying damage when the soil temps fall to around 20 degrees. Some tree species are more sensitive than others.

The temperature of the soil is not continual. There's always warmth in the earth. The ground could be freezing from the surface, but it's continually thawing from below. During winter, trees are adapting continuously to the changes. The main danger to trees is an abrupt deep freeze. As long as they have time to adjust, they're okay. It's when change happens unexpectedly that it can bring trouble.

This is the main reason to keep a layer of mulch over the roots of your trees. Mulch protects the soil, maintaining the warmth when the air temp plummets. If you need mulch or wood chips, ask a tree care company to supply you with some.

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