ONE OF the great garden investments (the returns are fabulous) is the pulling up certain weeds this time of year.

Or, for those who prefer open threats, if some of these weeds are not destroyed now next summer will be awful.

The dock is a great broad-leaved weed as handsome as a rhubarb. Time and again over the years, I have so admired it in the spring, when it gives a much-needed effect of luxuriance and lushness, that I have spared it. And always to my eventual sorrow.

The dock makes roots while the sun shines. There comes a time in its second beautiful year that only a major excavation will remove it -- to the detriment of any other plant within a yard of its subterranean fortress. t

The bindweed, that innocent-looking scrambler like a morning glory, is a major terror. Gardens have been abandoned because of it.

It sends up a thread, a mere thread, with little leaves disposed along the sides, and is not without charm at first. It roots (rightly are they called devil guts by countrymen) are easily seen and are easily forked up when the soil is mellow.

But what the gardener -- the new gardener, at least -- does not comprehend (for the young do not really understand horror) is that any fragment will sprout, and within a year will assume the world and all civilization within it.

Lesser terrors like chickweed, sprouting in the cool weather, are easily sliced off at the surface in fall and early winter, but if left until spring will do awful things to irises, pansies, sprouting columbines and so on.

I say nothing of nut grass. It is the worst of all weeds. I do not have it. I pretend nobody else does. You may have seen inquiries from gardeners in the country who ask what to do about nut grass. But I go on the theory they do not have nut grass at all. If they did, I would have it too.

I have personally dug it out 33 inches deep, and have personally seen its little strands 40 inches deep in garden beds that were excavated.

It can be eradicated, of course, just as rats and fleas and cochroaches can, but it is not a question of a squirt here and a squirt there, but of a lifetime dedicated to its conquest.

The only good thing I can think of to say about our too-cold winters is that nut grass is never more than a marginal weed with us. In my old garden, well southwest of here, it was dominant. Even if you fumigated the soil, which I could never consent to, killing all the life in the soil, the next wind brought in seeds. Covering with tar paper was the most workable control for many. But the best was hand-pulling, performed every five days for two years or two centuries. Eventually you could exhaust the thing, but many a good gardener got to Abraham's bosom without ever knowing the joy of victory over nut grass. But to get on -- an hour's assault on weeds now is worth two major engagements next summer.

Needless to say, this important task comes due at a time you are not doing anything else. You have no vast climbing roses to shorten or tie in, you have no bulbs to plant, no perennial stalk to cut out, no peonies to cut just at the point the old dead stems meet the underground red growth buds. You have no leaves to get out of the lily pool, no tropical nymphaeas to dig up and store, no cannas or gladiolus to trim and store, no tuberoses. No fences to repair, no sheds to paint, no miscanthus or arundo (elegant grasses both) to cut back. Your osmanthus and holly have not suddenly shot out curious leggy growths to be shortened. Your ancient plantings of crocuses and late-winter bulbs have long since been dressed (for the first time in five years) with sprinkles of potash and phosphorus.

Everything has been tied that needs tying. All stakes have been cleaned and stored. All tools ready for their winter rest. The chrysanthemums I rooted from cuttings and got off to such a fine start last spring were rather neglected (totally, if the truth is worth mentioning) and are quite a disappointment to me. I knew they would be, yet I am indignant.

Ruin and decay is all around I see.

In the pool, however, the golden ides (or golden orfe, as these orange cigar-type fishes are often called) have almost tripled their size since May. The infant goldfishes, mere amoeba 18 months ago, smaller than a typewritten letter I, are now five and six inches long.

That is because I got the rotted manure wrong in the earth for the tubs of water lilies and the water stayed a fine opaque green all summer, ruining the effect of course. All other years the water stays transparent black. But there is nothing like green water to make the fishes grow.

People who collect topazes or other junk have an easy life.

But then they never see them triple in size from May to frost.