Behold the beauty of frost’s many forms

I love the first frost. I’ve never joined the chorus of gardeners who view it as a disaster to be lamented. Sure, half the garden has been obliterated. High time! By then I’m tired of picking beans, finding homes for the extra squash, and feeling I need to can every last tomato.

Besides, frost is beautiful, whether it’s a sugary sprinkle of hoarfrost on the grass, the thick white fur of rime from a frozen fog, a glittery ice coating on twigs or the frost that paints the car windows. What a miracle that this plant-killing event should produce plant pictures!

Mathematicians explain that both ferns and frost are fractals — self-replicating patterns — which makes them no less mysterious. Take a moment to admire them before you scrape them off and start the engine. You have plenty of extra time, now that there’s no more weeding, mowing or trellising to do.

Certainly there are times when frost may come as, if not a tragedy then at least a disappointment. You were determined to make a big batch of pesto before your lush green basil became, overnight, a blackened, sodden mess. After all, it’s just common garden sense to foresee the coming of frost and plan accordingly.

Part of that planning is deciding where to put the garden in the first place. If your yard is small you may not have much choice, and simply finding a sunny spot may be a challenge. But if possible, choose a south-facing slope that tilts your garden toward the sun, holds onto the sun’s warmth during the day, and allows the cold night air to drain downward.

The movement of cold air is not as obvious as the movement of water, but its action is very similar, seeking the lowest level and creating “frost pockets” at the bottoms of hills or on the north sides of hedges and buildings. After a cold night you’ll see these areas mapped out for you in frosty detail.

Planting above a body of water that holds the sun’s warmth, or in front of a dark, heat-retaining wall will also help to protect crops. Robust plants grown in fertile soil also tend to be a bit more resistant.

There is a difference between a light frost that just nips the tops of the squash vines and a frost that kills all the tender crops and their fruits. These susceptible ones include warm weather vegetables such as tomatoes, peppers or beans and annual herbs such as basil and dill.

But for a great many other crops — the leafy greens, most of the brassicas such as broccoli and cabbage, and most root crops — only a “killing frost” will do significant damage. (With root crops and winter squash you have to be careful, because often the damage only turns up later, in storage.)

With hardy crops, the harvest can be extended even beyond early frosts by using cold frames, floating row covers and other protective devices. In fact, this is the best approach to frost’s inevitability. If you can’t beat it, put more of your energy into growing and protecting crops that will give you a longer season of enjoyment.

Developing a good instinct for frost also helps. Usually the first one of the season occurs during the week preceding a full moon, so be on the alert. If you have not had time to make that pesto, or that homemade ketchup, tune in to the weather report.

Even if the “F” word is never mentioned, there may be clues. A clear night, with no blanket of clouds to block the Earth’s radiational cooling, is a bad sign. Beware the calm night, with no wind to mix up the layers of warm and cold air. Or, the dry one, with no moisture particles to trap heat.

Seasoned gardeners have little tricks, like counting the Pleiades — if you can see more than five stars in that little cluster it’s a clear night. If you keep track, you’ll know what temperature at nightfall signals a frost is likely. That’s 42 degrees F at our house, but perhaps not at yours.

Caught unawares, there’s still time to run out to the garden with a flashlight and cover a crop with whatever is at hand — floating row covers, tarps, bedspreads — to trap the Earth’s warmth. Remove them promptly in the morning.

But ready, or not, frost comes. And when it does, it can be a great relief. Whatever else you might have done, it’s too late now. Why aren’t there folk festivals that celebrate the first frost, the way they celebrate the sowing of the corn, or the stomping of the grapes?

I say, rejoice in the death of the tomatoes and make a green salad from everything that remains. Put on a DVD of Edith Piaff singing “Non, rien de rien. Non, je ne regrette rien.” Then go check the glass on your cold frame for fractals.

Barbara Damrosch

Barbara Damrosch

Barbara Damrosch’s latest book is “The Four Season Gardener’s Cookbook.”
Barbara Damrosch

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