This winter has been one for the record books, and the bare branches of winter in the Mid-South make it hard to imagine a return of green life on our trees. But this long winter has actually been a time of preparation and restoration for our trees. If we could shrink ourselves down to see the preparations underway inside the roots, we’d be amazed.
When the soil temperature remains above 40 degrees—as it does in Middle Tennessee most winter seasons—the roots of our trees and shrubs continue to grow and expand right on through the cold days and weeks to prepare for the coming spring season. That’s exactly why fall is the best time to plant a tree here. It offers a head start for the new transplant, a time to get a grip in the soil before sugar energy has to be expended to put on new green leaves. Fall and winter are the seasons for the roots.
The shortened days and lack of sunshine trigger the shutdown of the leaves’ chloroplasts and put on display the color that has been hiding there. Functionally, the trees’ focus then shifts from the manufacture of sugar energy in the leaves to sugar use in the form of root hair growth in the relatively warm soil. Tiny root hairs—those non-woody, little blond filaments that can hide in a spade of dirt—are unseen, critical components that will be the new procurers of moisture and minerals from the soil during the next growing season.
With that being said, a tree is never really dormant. We just don’t see the growth going on during the winter months.