Last year about this time, I planted several rows of spinach, beets and turnips. I was intending to plant carrots and Swiss chard, too, but put it off and left a couple of packets of seed lying on the ground. I'm not a neat gardener.

To make a long story short, none of my efforts produced a great deal last fall, and I forgot all about the stray packs of carrots and Swiss chard. This past spring, however, brought a pleasant surprise. As early as late February (when we had a brief spell of early spring), the row of spinach began poking through the ground, followed shortly by some very vigorous beets, turnips and -- lo! the forgotten packets of chard and carrots sprouted healthy greenery too.

Now, one of my garden credos is that accidents almost invariably pay off better than plans, but this year I'll plant these apparently quite hardy veggies with the intention of getting a jump on next spring. I'll also put in leeks. Though I've never grown leeks with great success, I'm told they do well if allowed a start in the fall, rather than early spring, largely because of their lengthy time to maturity -- 120 days -- and their reputation for hardiness.

There are certain vegetables that are tried and true in wintering over: Onions and garlic do well, as do chives. There are several schools of thought on just how to get maximum yield from fall-planted onions. I've always advocated mulching after planting to guard against changes in ground temperature. But one reader wrote last spring to say that he mulched his Washington garden but didn't mulch his country garden, and his onion crop was much greater in the country. He plans on planting again this fall, but won't mulch. Another gardener claims that mulching onions sets in the fall encourages mice to burrow and eat the onions.

I'd venture to say that mulching probably isn't necessary, since onions are quite resistant to our winters. And don't forget that a blanket of snow makes an excellent insulator against changing temperatures.

Plant onions and garlic as you would in the spring -- to a depth of about four inches. Incidentally, I've had no problem finding onion sets this year. Last year, you may recall, the onion-set harvest was delayed by late summer rains, and many readers wrote and called saying they were difficult to find. I've already bought my onion sets, and the hardware store where I get them reports an ample supply. They certainly are in earlier than I can ever remember.

Garlic is available at grocery stores. Just make sure you buy garlic in bulk rather than packages: You want the largest cloves you can get; the small-cloved garlic that sells in packages is very unsatisfactory for planting.

One year I was clever enough to prepare my potato bed in the fall. It paid off with a spectacular harvest, mainly because I was ready to get the seed potatoes in at the earliest possible time, thus avoiding the height of the potato beetle season. It locks you in somewhat when you're ready to plan your garden, which I never get around to doing until the seed catalogues arrive. But, if you can live with that constraint, it's worth a try. Dig your trenches a little deeper than you would in the spring, because rain and snow will wash some of the soil back into the trenches over the course of the winter. If you're wise, you'll cover your potato trenches with a mulch of leaves or hay, which will help prevent silting. In late March, when it's time to plant your potatoes, the job will be easy -- just pull the mulch back, drop in the potatoes and cover them with the mulch.

Trenches should be six to eight inches deep and 18 inches apart. Good, loamy soil won't need to be loosened again in the spring (freezing and thawing does a good job of that) but if your soil, at such a depth, is quite heavy with clay, you may want to add a couple of inches of sawdust, which will be well composted by the time you put in your potatoes.

As a matter of fact, now's a good time for a general application of sawdust on those gardens that suffer from too much clay. Clay soil is often poor in nutrients and won't retain moisture on the surface -- a must for young seedlings. You may have found that young seedlings get washed out with heavy spring rains if planted in heavy soil.

It's difficult to say just how much sawdust you'll need to cure the problem -- each garden is different. But one thing's for sure: Even the freshest, greenest sawdust will be well seasoned and probably thoroughly absorbed by spring if you add it now. Add some lime at the same time to help control the acidity that sawdust will lend to the soil..