It always starts about this time of the year. It begins with something small. I notice yet again that the cabbage has been eaten up by cabbage moth caterpillars. And I think, "Next year, I'm really going to keep up with Thuricide treatments to keep the little buggers away." Or it occurs to me that now is the time to put in garlic if I want a good crop in early spring. Or that this year, I'm going to try leeks. I'm really going to do it. And it develops into a virtual symphony of a garden -- visions of lush greenery producing bushels of unblemished vegetables. Of finding obscure varieties of squash nestled under giant leaves. Of picking, with a squeaky crunch, arm-size ears of corn off seven-foot stalks. And each glowing thought is prefaced by the words "Next year. . ." There's always next year. But now is the time to do something about it.

DON'T WAIT TILL SPRING: In a garden, spring cleaning should be done after Labor Day. It doesn't take much time. On Saturday morning, take an hour to look around the garden and decide what can be pulled up and thrown into the compost pile. Section or cordon off that part and look around for something that will serve well as a winter- over mulch. Leaves, which are starting to come down now, are good. Grass clippings work, although they tend to mat and should be mixed with something that will keep them loose -- like straw. Straw is wonderful, and if it looks a little junky at first, by the time spring rolls around, it will have taken on the color of the soil. Bark mulches, available in bags at most garden centers and grocery stores, are the easiest and most attractive, but also the most expensive. Mulching helps condition the soil, retain winter's water, reduce erosion and keep the worms snug during the cold.

ONION OGLING: For the biggest, fattest onions in spring, put in sets now. Onion sets, which look like little pearl onions but aren't, are available now at garden and hardware stores. Find a small area in your garden that will be easily accessible in early spring and won't be disturbed by the activity that always signals the arrival of warmer weather next year. Plant about a pound of the sets four inches apart if you've got good enough soil for a little crowding and six if not, four inches down, and cover them up with a light mulch, maybe two inches. Garlic sets can go in now, too, for the same purpose -- larger fruit in the spring. Get a couple of garlics at the grocery store -- choose some with large, fat cloves -- and plant them the same way as the onions. You can also put in onion seeds now. They'll get a little start in the fall, will winter over nicely with mulching, and come up in early spring as green spring onions, and if you leave them alone, will mature as regular onions. Leeks can also go in now. They take forever to grow -- 120 days -- but are such a treat that they're worth fooling with. The nice thing about putting them in now is that it eliminates the need to start them early in flats indoors.

BUSH LEAGUE: I was soundly derided last week by my gardening friends for buying forsythia bushes. "You paid money for those?" they asked with amazement and some ridicule. Forsythia, you see, is widely considered a weed around here. I happen to like the stuff tremendously, and so do my gardening friends, but they urged me to come help myself to shoots from their prolific forsythia bushes. If you have friends like mine, find new ones. But before you do, get your shovel and dig up some of their forsythia shoots, because now is the time to get them in for masses of spring color. Or do what I did - liven up the borders around the house, where annuals have nearly stopped blooming, with golden and sienna mums.

GERANIUM GYRATIONS: One of the gardening friends who laughed at my buying forsythia also gave me some good advice on wintering geraniums. I guess I'll keep her. "First you cut them way back," she said, noting that her potted geraniums grow as much as two or three feet in the summer. "To maybe about eight inches. This is also a good time to repot them, you know, if they need larger pots." I'm sure she meant that this applies to the really bigger, older plants, because everyone knows that pot-bound geraniums produce better flowers. "Then I put mine on my back porch, which is closed in with screens, to get them acclimated to being inside, out of the wind. Then they go onto the front porch for the winter, or under grow lights in the basement." It should be noted here that this lady's front porch is also closed in, but with transparent plastic, which produces a greenhouse-like environment during the winter. But for now, the thing to do, it seems, is to cut back your geraniums -- some people recommend even more radically than my gardening friend, to about three or four inches -- and root the cuttings for additional plants to give as Christmas gifts. Keep them watered and fed about once a month to prevent leaf yellowing, and, with grow lights, they should continue to flower.