The Garden in Winter

  • Damon Winter/The New York Times
  • Damon Winter/The New York Times
  • Damon Winter/The New York Times
  • Damon Winter/The New York Times
  • Damon Winter/The New York Times
  • Damon Winter/The New York Times

Winter Is a Lie

We cry that the earth is draggy, the garden defunct. But as usual we’re actually whimpering about ourselves. In his poem “Snow,” published in the September issue of Poetry magazine, Frederick Seidel touches the great white void:

Snow is what it does.
It falls and it stays and it goes.
It melts and it is here somewhere.
We all will get there.

Maybe it’s a koana puzzling, often paradoxical statement, but wherever “there” is, I’d rather be someplace else.

Which takes us back to the lie of winter — or shall we call it a misunderstanding? For in truth, our gardens haven’t gone anywhere at all. It is we who have elected to migrate someplace else for the season; that is, to a cocoon made of duvet, cookie crumbs and tubs of Eucerin.

A week or two ago, I stirred myself from such a couch coma and set out to discover the lost continent called “outside.” Here is what I found. The grass was not dun-coloredyellowish-gray, but green; the ground was not frozen, but soft underfoot. Camellias were in bloom — outside the great glass conservatory at the New York Botanical Garden. And crocus bulbs were breaking ground just north of 59th Street in Central Park.

Apparently, it was time to do a rethink of January in New York.

Dormant, but not forgotten

My first field guide was Renuka Sankaran, a 36-year-old assistant professor of biology at Lehman College of the City University of New York. She started by overturning one of my fundamental misconceptions: most of the plants I could see in the home garden area at the botanical garden were not struggling to stave off death. They were comfortably dormant.

“The grass and the evergreens are really well prepared for their stress at this time,” Dr. Sankaran said. “They’ve gone through a pre-dormancy period. It’s how they become cold-resistant.”

She pointed to a stand of conifers, mostly tall firs, on the park’s perimeter. In the fall, a tree’s leaves or needles begin to detect environmental cues. The nights roll out the black carpet. The daylight hours also grow shorter, but a tree, like a teenage goth, heeds darkness. (“It’s just semantics,” Dr. Sankaran said — or, perhaps, the province of the philosophy department.) Temperatures fall below 4 degrees Celsius39 degrees Fahrenheit for a couple of hours before dawn.

This would be hat weather, except that few trees own hats. Instead, a cold-tolerant plant starts to produce abscisic acid, or ABA. This stress hormone travels through the sap and activates a set of genes that, in turn, produce cryoprotectant solutes in the cells. In a phrase, plant antifreeze.

“We don’t know a lot about these,” Dr. Sankaran said. In a broad sense, when a plant runs into severe cold, “The water cools really fast below the theoretical freezing point of zero Celsius. And it maintains its liquid state. It can go to negative 40 Celsiusnegative 40 degrees Fahrenheit,” or even a few degrees lower.

The temperature at the garden around noon was closer to 40 degrees Fahrenheit. The sun was putting in an honest day’s work. On an afternoon like this, Dr. Sankaran said, anything green was probably photosynthesizing. “You can’t take a ruler and take a measurement of the grass,” she said. “It’s not going to grow much at all.”

The rule for a hardy species in winter, as the late Curtis Mayfield might have put it, is to keep on keeping on.

For all her comfort with cold-climate botany, Dr. Sankaran said that she had gone through her own period of winter shock and acclimatization. “I grew up in the southern part of India,” she said. “I didn’t ever have to wear a jacket, a sweater, ever.”

When she arrived in southern Illinois 14 years ago to continue her university studies, she observed autumn color for the first time. “The campus was so beautiful. I loved my fall. It was as I’d seen it in the movies.”

“It was the same that winter, too,” she continued. “Until I stepped out on the ice. And I hated it.”

A dry cold

You can bull your way through winter, or you can wait it out. Patience is the guiding principle for the shameless leaf-shedders, said Jamie Boyer, 41, an evolutionary biologist and the vice president of children’s education at the botanical garden.

“We think of deciduousness connected to cold,” he said. “Ultimately, it seems to be a condition that’s developed to respond to drought. We see them” — that is, deciduous plants — “in tropical dry areas.”

You could almost call it a matter of self-restraint, an angiosperm’sa flowering plant version of Lap-Band surgery. January’s frozen ground brings a dry spell. Yet, Dr. Boyer said, “on a nice sunny day, if that plant had leaves, it would want to photosynthesize. If water is limiting, that’s going to cause problems for a plant. It’s like sucking on a straw with nothing at the bottom of the cup.”

It helps here to picture the hydraulic system that is, say, an oak tree. “As long as the temperature is warm and they’re exposed to light, their stomata are going to open,” Dr. Boyer said. “Water is moving through them. It’s almost a passive process.” Dozens of gallons of water (some 90 percent of each day’s drink) transpire through the leaves and into the air.

And if the ground is dry? Ditch the leaves.

The rhododendron, a broadleaf evergreen, was playing out a different gambit. “It has decided to hold on to its leaves,” Dr. Boyer said, which are “tough and leathery.” The result is that the plant “can be doing some photosynthesis on a day like this, where this Japanese maple there has nothing going on. You lose today, buddy!”

Dr. Boyer is the co-director of the garden’s citizen-science program, which dispatches participants around the grounds to make phenological observations. That is, to detail the seasonal changes in the environment.

Before you can make sense of phenology, you have to recognize the plants. It wasn’t until 1819Parishes and towns in the Burgundy region of France have recorded the date of the pinot noir grape harvest every year since 1370. that the botanist John Torrey published the city’s first thorough flora, “A Catalogue of Plants Growing Spontaneously Within Thirty Miles of the City of New-York.”

Methodical phenological data at the botanical garden goes back just a decade. But it was Dr. Boyer’s nonscientific reckoning that bulbs appeared to be shooting up at the garden this year “pretty stinking early.”

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