Christmas Day finds this garden writer really scratching his head for something to write about. Something besides holly, mistletoe, poinsettias and balsam fir, that is. Could it be that six years and eight months of writing this column have brought the author to the end of his ideas? Maybe mortal flesh isn’t capable of writing more than 350 columns on gardening.

Whenever I get to feeling this way, I think about my father, who taught introductory botany to a new crop of college freshmen each year for 32 years without a sabbatical. I took that class from him after he had been doing it for 22 years, and it was clear to me that he hadn’t lost much of his original enthusiasm for the subject. The microscopic comings and goings of little green cells — what glib TV comics would dismiss as pond scum — still fascinated him, still engaged him not just intellectually but emotionally as well.

What, after all, is the point in looking down a microscope and witnessing the tiniest details of nature’s creations if you don’t allow yourself to get involved? The myth of the pure scientist — studying things with a cold, dispassionate eye — is nowhere more foolish and insupportable than in the botany lab.

“Plants are the most moral creatures,” my terminally idealistic father was fond of saying. “They just produce and produce, all day long, while we animals merely consume, pollute and leave things less tidy than the way we found them.”

So, if Christmas is supposed to be the most moral time of year, maybe the idea of “green morality” is worth writing about. Heaven knows that human morality suffers from all the publicity it can stand in the month of December.

You don’t have to be a botanist to understand the idea of green morality. In fact, more than one botanist has missed the point entirely by concentrating on the drier aspects of plant science or getting all wound up in biochemistry.

No, I think gardeners are more apt to have an intuitive grasp of what makes plants the moral beacons that they are. At their best, gardeners are people who put seeds and seedlings in the ground as an act of faith. They commit themselves to the preservation of each little propagule and, in so doing, relinquish a special part of their heart to the green world. When the plant grows, flowers and sets fruit, the commitment is rewarded and the bond strengthened.

It’s a bit like parenting, but also uniquely different because of the vast gulf of evolution that separates humans from plants. In the pivotal moment when the river of life diverged to produce plants on one side and everything else on the other, the stage was set for literally billions of years of conflict. In a way, the dominant theme of evolution can be seen as the endless strife between producers and consumers. Through all the eons of being munched upon by slimy, slithery, crawly creatures and then dinosaurs and warm-blooded creatures, plants kept on growing, changing into ever more sophisticated forms, improving their strategies for survival. It’s a wonder they never lost heart.

And finally, along come Adam and Eve to change the course of things forever. Their offspring, blessed with the God-given ability to appreciate things as quiet and subtle as a patch of jade-green moss or an ancient, gnarled conifer, have learned to love plants and yearn for their salvation.

Green morality stems from the wonder and mystery of plants, and it flows through the equally marvelous creation of human beings. Where it goes from here is the great question. Will we learn from plants to love one another? Heaven only knows. Will we learn at least to love all the plants that remain in our global garden? Let’s hope so.

Michael Zuck of Bangor is a horticulturist and the NEWS garden columnist. Send inquiries to him at 2106 Essex St., Bangor, Maine 04401.