This is a good weekend for a big project, with three full days ahead.

It's a time for harvesting the garden, preparing your storage area for the fruits of your labor and, if you're one of those types that care about a nice lawn, for "thatching" and "spiking" -- two terms that sound far more wonderful than they are. PESTO PEP -- The best way I know of to preserve basil is in pesto. This fragrant European preparation goes with all kinds of soups, breads and vegetables and will solve the problem of boring noodle side dishes for the rest of winter.

The world is divided into two kinds of people -- those who don't grow basil and those who make pesto. It's a mixture of gobs of basil leaves (don't use the blossom -- it'll make a bitter pesto), garlic, olive oil, cheese and pine nuts or walnuts, if you have them handy. You mix it up in a food processor pouring in the olive oil slowly, and store it in a jar at the back of your refrigerator, where it will keep forever. When you open up a jar on a chilly winter evening and coat your home-made noodles with the pistachio-colored paste, it's like tasting a fresh summer morning. Cut back your basil this weekend and make up plenty of pesto. The basil will grow back enough before frost to allow you another cutting for dried or frozen basil later. SHELVING FRUIT -- Get your basement ready to receive winter vegetablers, which you will pick a little later on. Pumpkins, butternut, acorn, turban and hubard squashes, rutabagas, turnips, beets and apples will all keep into late fall and some right through the winter and into next spring, if you handle them right.

Naturally, you've already carefully stored your onions, garlic and shallots in handsome French string shopping bags, after allowing them to dry off completely, right? And your potatoes, of course, are nestled comfortably in a cool, dark place at the back of the basement, so that light will not turn the skins green and indigestible.

When buildings shelves for your winter vegetables allow about a foot of space between them for maximum air circulation around the smaller squashes, and two feet or more for the big pumpkins. Put in plenty of shelves, because the vegetables and fruits have to be in one layer and not touching one another. Apples and root crops will probably be eaten first, since they don't keep as long as the hard-sheeled winter squashes.

Think about where you're going to put the green tomatoes you'll be snatching off the vines the night before the first frost in October. You'll only have to accommodate them for a couple of weeks, spreading them out and covering them to ripen in the dark, before you put them in canning jars or in your freezer. LAWN LABOR --- Frankly, I, personally, pay very little attention to my lawn. When it gets about calf-high, I call Brande, the 16-year-old who lives at the end of the road, and she comes down and mows it. There's a lot of crabgrass in it, plenty of dandelions, some wild violets that bloom in May like a plum-and-white speckled carpet, and lots of creeping Charlie --- and, I have to admit, a few thistles, which attract the small yellow-and-black finches. But when it's all mowed down to the regulation 2 1;4 inches, the lawn looks, to my undiscriminating eye, remarkably like those carefully manicured jobs you see adorning Potomac estates. Thus, the following advice comes from talking to others, reading a little, and no personal experience: "SPIKING" is tedious work but sounds as if it might be good exercise. Because most people don't have a spiking tool, which looks like a giant paint roller with a bunch of spikes on it, you're supposed to take your large garden fork and stab holes all over your lawn, about six to eight inches apart. Then you pick up some slow-acting fertilizer --- either a prepared mixture or an organic fertilizer mixed with peat and sand. Consult on amounts with your extension agent or someone at your garden center who knows what he's talking about; every area differs in soil requirements. Sprinkle the fertilizer about so that it gets into the little holes you've put in your lawn. Rake it down, add seed to bare patches and wait for spring. If the lawn still needs regular mowing, remember to keep the mower set on high. "THATCHING" is basically raking the lawn so that you pull up old dead grasses that become buried under the live stuff and prevent adequate air circulation. After you've thatched you can top-dress the lawn with new seed, but don't do this quite yet. October is the best time for top-dressing.