During the winter months, trees and other types of plants are not as dormant as we might think. While the growth process does slow to a crawl, life continues to stir deep in the soil at root level and at the ends of branches, where concentrated energy ultimately results in new growth best exemplified by leaf production.

Swollen and vibrant, these small buds await nature’s cue to open, an event that takes place in this part of the world from late March to early May. Called scales, the tough outer shells of the buds will gradually separate, giving way to whatever type of leaf a particular tree produces.

An examination of a typical maple tree branch made at this time of year shows most of the buds growing from short twigs, and which all, without exception, curve upward, and for good reason: The leaves that will eventually emerge from those buds will need to interact with the sun for food production, they must grow so that their tops face the sky. Short of this, these small solar collectors cannot properly do the work of trapping the sun’s energy and redistributing it among food-storage cells in the leaves known as chloroplasts.

The placement of the buds along the twigs is also no accident. A single twig can bear one or two buds, while a composite twig made up of several short stems may sport a dozen or more. A twig has one terminal bud, or the one that appears at the very tip of a branch, and several other lateral buds that grow farther down. The terminal bud isn’t always necessarily the largest, but it represents the end point for the leaf production on any given branch that will continue to elongate via cell displacement like the tree to which it is attached.

The leaves on a tree are classified according to several different criteria, including their placement on the twigs, their shape, the smoothness of their edges, their texture and their veining. Depending upon what type of tree it is, the new buds that will give way to leaves are placed along the twigs in a predetermined and strategic way according to the nutritional needs of the tree and where it happens to be growing. Generally speaking, the larger the plant, the larger the leaves, as it all has to do with how much energy the tree needs to survive. It’s not unusual in the fall in a deciduous forest to see a fallen leaf the size of a football, and it probably fell from an oak or a maple that’s been around a long time and has a very large appetite as a result.

What is perhaps most remarkable about all plants is that each of their parts, from root to terminal bud, is an independently functioning entity that works in conjunction with all the others toward a common goal-to keep the plant alive. It won’t be long now until just the right combination of rain, sunlight and heat will transform these humble buds into the leaves that will make the world green again. And it is all going on in the tree branches swaying in the wind just outside my window.

— Rachel Lovejoy, a freelance writer living in Lyman, who enjoys exploring the woods of southern Maine, can be reached via email at [email protected].