As the temperature drops and fall changes to winter, it's time to pull some covers up around your garden. A quilt made of almost anything, from fallen leaves to feathers, will keep your plot cozy and make spring planting easier. And it will keep your outside herbs and cold-weather crops in better shape while it fertilizes the garden.

If you've mulched with hay, that's a start, but, just as lots of layers keep a person warmer in winter, layers will do more for your garden plot.

Start by encasing your herbs in little shelters made of branches, then cover the branches with a thick mulch of hay. And pull a heavy mulch around the Brussels sprouts and any other cold-weather crops still growing.

Then use your imagination to come up with a covering that will be both warm and nutritious. You can use whatever's available, but directions might go like this: Spread a covering of hay to the edges of the garden and cover it with a layer of fall leaves. Add a few touches of lime or rock phosphate, a little fish meal, grass clippings, bone or blood meal and fairly fresh manure. Cover with more leaves, hay or even old newspapers, and let it sit in the sun for the winter.

When you've actually making is a big sheet of compost, so you can add some of anything else that will decompose: coffee grounds, eggshells, banana and fruit peels, even the trimmings from your latest haircut. To make sure it breaks down, you need some fresh manure. If you can get out to farm country, you're almost sure to find someone who'll let you carry away all you want. With cow, horse or sheep manure, you can use a thick layer, but with the stronger, more concentrated chicken manure, you need only a thin layer.

By spring, you can pull back the covers and find that everything but the top layer has turned into a rich and humusy blanket of compost. And all you'll have to do is turn it over and plany.

Even if you've never had a garden before, if you cover a patch of lawn this way and wait a winter, by spring the patch will practically be a garden. The covering will kill the grass and break down the sod, and save you a lot of time spring.

When other first-time gardeners are struggling to break sod in spring, you'll be a few steps ahead of them. While they're breadking their backs, you can break your ground almost effortlessly. And you'll have more earthworms, which, warm through the winter, will be ready to go to work.

Earthworms, like gardens, love a warm bed for the winter. When you pull back those covers, you'll have more earthworms, which, warm though the winter, will be ready to go to work.

Earthworms, like gardens, love a warm bed for the winter. When you pull back those covers, you'll probably be surprised by the worms in residence beneath it. They'll tunnel through the earth, improving drainage, and fertilize as they go.

If you're a longtime gardener with a thriving fertile plot, you'll hardly have to disturb your worms or your garden to begin your spring planting: Just pull the mulch back in rows and plant your seeds in the rows. It's the easiest way to garden. Ruth Stout, who devised the year-round mulch method, called it "No-Work Gardening." You don't have to turn over land or weed between the rows because the mulch does everything.

I seem to move too much to ever get a plot this rich, so in spring I usually turn the covers right into the soil and begin to accumulate a new layer of mulch. The decayed organic matter improves the soil and makes it more like a sponge to hold water for the plants. The crops get bigger, prettier and, of course, tastier.

So, when the weather turns harsh, put your garden to bed and pull those covers all the way up, because, baby, it's going to get cold outside.