The garden in winter. Photo by Barbara Damrosch. (Barbara Damrosch/BARBARA DAMROSCH)

If you are reading this after 5:30 a.m. Coordinated Universal Time (that’s 12:30 a.m. in Washington) on Dec. 22, an important moment has occurred that you should pause to observe. It’s the winter solstice, when the days stop shortening, reverse direction and begin to grow long again.

If you pay attention to these things, you’ll notice a lag of a few weeks between the time the sun begins to set later in the day and the time it rises earlier. But the 22nd is, nonetheless, in the northern hemisphere, our shortest day, and the one in which the sun hoists itself the most miserly distance above the horizon. To top it off, the daily rate at which the sun sinks lower in the sky has been slowing, until it stops. Hence the word solstice, which means that the sun “stands still.”

It’s only for a theoretical instant, of course, but it can often seem, during these days of dark and cold, as if life itself has ground to a halt. Gardening can take place in the jewel boxes of our cold frames and greenhouses, but with growth so slow that there is little for you to do. The hibernation practiced by some creatures starts to seem like a great idea, and the southern migration of others a possible plan.

Not surprisingly, the human celebrations held in this season are full of light, whether it’s from Hanukkah candles, bonfires or sparkly tinsel draped over trees. You can almost understand why people light up their lawns with electrified reindeer. The longer the nights and the greater the inactivity they foster, the more we need our spirits lifted.

But at the same time, I’ve often heard gardeners say how much they look forward to this time. The fall chores are done and they want to catch their breaths and not weed, not feed, not pick. They’re not even ready for the seed catalogues that seem to show up earlier each year. This is the time to sleep later, cook soups from the root cellar and wear pants without muddy knees.

There’s also a certain justice in the fact that while winter’s cold is just beginning and will reach its worst in late January and early February, the light has now, officially, started to return. In a few weeks, just when the heating bills are highest and your down parka gets the most use, you’ll see the herbs on your windowsill sprouting green tips, thanks to the 10-hour day, which occurs in Washington on Jan. 25. That’s the magic number that seems to induce spring growth. Even in a unheated greenhouse, this growth begins, as light trumps warmth in its effect.

In nature, the dark has its use. Many plants will not bloom unless triggered by a stretch of longer nights: chrysanthemums, for example, with their fall flowering. Maybe gardeners have a similar photoperiodic need, for the darkness that drives them indoors, even if it’s just for a brief hesitation, like the sun’s, before they roll up their sleeves again.

Damrosch is a freelance writer and the author of “The Garden Primer.”