The weather at Mount Vernon would bewilder George Washington

Many aspects of George Washington's Mount Vernon estate in the 21st century would be familiar to its creator, who was born 285 years ago.

The mansion, for years painted bright white, is now daubed in the subdued greenish-beige hue that the first president would have known. His fanciest garden, the Upper Garden, has taken on a more utilitarian feel over the years as more became known about its 18th-century design. In the Fruit Garden and Nursery, Washington would recognize the braided raspberry canes, the locust stumps fashioned into a living fence and the root vegetables grown for their seed.

One element of the winter garden might not seem so normal to Washington: the winter itself. Once consistently cold, the season has become predictably unpredictable in these parts.

In Washington's day, gardeners set about pruning the apple trees at the start of winter. The trees here in Northern Virginia no longer enter dormancy in December. "They still have their leaves," gardener Kristin Prommel said. Men cannot harvest blocks of ice from the adjacent Potomac River and its creeks. Yes, this practice is history now that we have refrigeration, but it's been decades since the river could be counted on to freeze over.

We live in an age of generally milder winters and, more important for the gardener, one in which temperatures seem to lurch from frigid to balmy.

This isn't all bad. When the soil isn't frozen, you can sink posts for fences and trellises, you can work and amend the soil, you can haul compost. Laboring for hours in 45 degrees is a lot more pleasant than at 25 degrees. But there are downsides.

The gardeners here fret that insect pest populations such as cucumber beetles and harlequin bugs will be back with a vengeance in the next growing season. But the biggest worry is that once trees and shrubs are coaxed into spring growth, once the protective bud scales drop and the blossoms open, freezing temperatures will return to kill tender shoots. This is a particularly pressing concern for fruit growers, because damaged flowers mean no fruit.

Fruit orchards were an essential element of Colonial plantations. Sugar was scarce and expensive, but fruit could be preserved and stored for months after harvest. A fresh apple or peach was one of life's great indulgences.

Nowhere is this significance captured better than in the Lower Garden, which is in some respects the least authentic display garden at Mount Vernon, being more of a Colonial Revival take on Ye Olde Virginia plantation. A mirror image of the Upper Garden, the one-acre, walled Lower Garden is my favorite garden at Mount Vernon because it lends grandeur and dignity to the lowly vegetable, as well as the loftier fruit espaliers.

The espaliered peaches, apricots, apples and pears that line the brick walls of the garden are representative of Washington's time here, but the apple and pear cordons that flank the paths are from the early-20th-century reworking. Some are 80 years old, and in the care of gardener Edward Harrington. There is a lot to prune - trees grown as cordons, fans and candelabras take far more grooming and training than regular trees. With winter pruning season now more compressed, the weeks around Washington's birthday are a busy time.

The key to maintaining control over espaliers is to trim their stems during the growing season as well. In summer, Harrington can be found snipping back vegetative growth, getting to each of more than 100 trees every two weeks.

In February, he thins out the thicket of stems growing upright at the top of the cordons. The twigs that he leaves will be frothy with blossoms in April. He will remove these after flowering, knowing that fruiting spurs lower in the horizontal branches will bear plenty of apples in the season ahead. He wants to keep the hedges low enough so visitors can look over them to glimpse the expanse of river in the distance.

Over the years, he has become more conservative with his pruning. "On an old tree like this," he said, showing me one of the original trees, "you have to be very careful with it and not take too much off."

Across the lawn in the Upper Garden, Prommel points out a plum espalier near the Georgian brick orangerie that is showing color in its buds. "It looks like it's about to start flowering, and it's February. It's been a weird winter."

The thought of its getting zapped by frost unsettles her, but she is glad to be pruning the fruit trees. "Pruning season is, like, I'm a real gardener again. Composting doesn't feel like gardening to me because you're not handling the plants."

Harrington wears a long peaked cap and wraparound sunglasses that hide much of his face. The temperature is above 70 degrees in advance of a snowstorm that turned into a bust. His cheeks seem a little sunburned, but maybe it's the wind.

Once his winter pruning is done, he will attend to the other plots in the Lower Garden. Next will be forming tepees for the garden peas, which will be pushed into the cold earth. He will put in the cabbage and lettuce transplants now growing in the greenhouse. He will pull back the thick mulch of straw on the extensive strawberry beds so they can flower freely in early spring. He will trim back the herbs in advance of spring growth. "It's a very dynamic job," he said. "You have to work with the weather."

And Old George, what would he make of it? "I think he would be proud of what Mount Vernon is today. It's a place of education and where we keep his legacy going, what he did here with his beautiful gardens and farm." Harrington adjusts his hat. "It's an American treasure, really."