A GARDENING FRIEND of mine has quite lost her mind, not that it distresses her much, and no longer makes an effort to conceal madness.

I estimate the garden to be 20 by 22 feet, and she started out all right, a few years ago, paving the center with brick and acquiring a little table and four chairs, with a rose, lilac, camellia, a few lillies, a peony, a grape and so on around the edges.

Everyone thought she had done well. But of course it didn't last. At first, she dissimulated about things, and was much given to saying:

"Oh, I think you have seen the Japanese anemones, they've always been here." She said things of this sort when she had broken down and been tempted beyond her strength by a catalogue or garden center.

She was very bad about garden centers; we all noticed that from the beginning. She would go on some stated mission of acquiring a sack of peat moss, but would surreptitously (entering stealhily at night, I suspect) bring home several flats of snapdragons and the Lord only knows what else.

It got to the point things were planted on top of each other, so of course many of them did not flourish greatly, and this gave her an excuse to yank them out.

"I cannot think why the platycodons did not perform this year," she would say, pretending to be puzzled why they were no longer there and (suddenly) 10 lily bulbs were.

But as time passed, she dropped all pretense. That much, at least, was a step in the right direction, no doubt.

It all came to a head when she converted a basement room (in which an unfortunate maid had once lived, it was said, though even in the old days there were laws against open cruelty, surely.This room has one small window, so she painted the whole thing white and installed enough special lights to illuminate the Capitol, and got someone to build a batch of stages on which she set as many post and flats of dirt as could be managed.

She no longer hid her packets of seed. They sat there in great rows. She had 200 packets of seed at once -- eggplant, tomatoes, thunbergias, snapdragons, zinnias and endless other things.

"Do you think you have room for eggplants?" her saner friends would say -- before it finally dawned on them she knew herself that she was mad, and did not wish to be sane.

"I've got some big pots for them," she would say in November. Sure enough, in February, the eggplants would produce some tumescent objects which she said were eggplants, and which she proposed to eat, until somebody told her (for no good reason, except the eggplants looked loathsome) that if she ate them, they'd kill her since they were obviously poison.

She persisted and recently set great pots of eggplant on the brick pavement of the garden.

She whacked back the climbing roses to skeletons, sawed down the camellia and two young magnolias, ordered great quantities of asparagus, strawberries, and half-barrels, in which she said everything would fit beautifully. A fig, a plum and a peach were supposed to live in barrels. As for the strawberries and blueberries, she said she was going to take up the bricks and build ziggurats where the table used to be, and on the little terraces, she said, the strawberries and much else would grow to beat the band.

She said it was silly to give all that space (about 12 feet square) just for people to lounge about drinking coffee and eating apricots. The only reason there are any bricks at all (the tiny paved area stil remains) is because she could not figure how to take the bricks up herself, and none of her friends would have any part in the project to take them all up.

Once, in a rather bitter jest, I suppose, someone offered her some little sequoia trees in pots. She accepted, but I never saw them planted out.

There is a vast space of wall, about 28 inches wide, beyond the French doors, in which she planted a trumpet vine, a quite vigorous grape, several clematis, and when they did not grow as rapidly as she thought they should, she filled in with blue lobelias and I think heucheras along with petunias, alyssum, and whatever else the garden centers happened to be selling.

Unfortunately a very fine musk rose flourished and has reached well into her bedroom windows on the second floor, and an admirable pink honeysuckle has defied all law and reason and settled in lavishly on an iron railing she installed for it several years ago. Rammed up against the iron spindles are perhaps two dozen sorts of perennials, some of which (including the white campanulas) are trying to spread, while others gallantly hold on as long as breath holds out.

Where the produce of 200 packs of seed, growing madly in the basement, are supposed to be planted in this garden, nobody knows.

This is an extreme case, of course, of the affliction common to almost all gardeners, and I mention it to make everybody feel much better. Most of us, after all, merely have to wander about the garden holding a new rose bush, wondering if it could not perhaps be tucked in between the hollyhock and the peony, since there is a good 10 inches there, and beyond doubt the hollyhock can be tied up a little and pulled to the left.

We do not, most of us, wonder where to plant an additional thousand seedings raised in the basement in a 20-foot garden already jammed beyond hope.

My friend, as I say, does not seem to suffer much. She is tremendously busy throughout the year, and has mastered the fine art of the scalpel, opening little slits here and there for one more plant, and she has become expert at last rites for the dying.

On the whole, she is happier than she was before this madness set in. We who like her, however, are in some distress where it will all end.

Still, as her friends tend to comfort one another when her name comes up, she's in better shape than if she took up raising cattle. A thing that mercifully has not yet occurred to her.