You may feel we are in the throes of winter, but for many trees, it is already early spring. How can that be?
In the late summer, trees begin to enter a stage of deep sleep called dormancy. They don’t stop growing because it is cold, they stop growing because a combination of long nights and cold sets up a complex hormonal response. If you take a twig off a tree in late fall and bring it inside, giving it plenty of light, warmth and water, it will probably do nothing. It is not simply asleep, but dormant, and only one thing will wake it up – more cold.
By now, in most North Temperate regions, some trees have gotten enough cold to overcome dormancy. They are poised to begin growing as soon as the weather improved. Other trees are not ready yet – they need more cold to overcome the dormant state.
If you are a careful observer, you should begin to notice buds beginning to swell, bud scales changing color, and even a few trees beginning to show flower parts. These trees are ready for spring and only need a few warm days to begin growing. In my area, red maple, silver maple, and elms are ready to go.
If you don’t want to wait, try bringing some twigs inside. Set them in water like a flower arrangement, and see what happens over a few days. Some trees will do nothing – they are not yet ready and need more cold days. Oak, beech and hickory often require longer periods of cold. Other trees will pop in a few days.