BY THE third week of April we have not only the azaleas in full bloom but also buds on the big clematis, in the tall irises, on all the early roses, and the gardener is almost persuaded he has lived through the winter once again.

"Cast ne'er a clout till May be out" is an old and wise saying, however, and gardners soon learn to distrust zephyrs. No sooner do you set out a clematis that has been given careful treatment in a pot since late February than zonk, over it keels when the soft growth encounters a night in the low 30s in late April.

But this sort of thing is a gardening constant. A friend of mine lost an akebia vine during the winter (though it is hardy in Boston) and a red honeysuckle bred in inland Canada.

I myself lost most of my Japanese irises and, a far more grievous loss, Rudbekia maxima which does not appear to be in commerce and the Lord only knows how I shall be able to replace it. It's an American wild plant, so naturally it have never occurred to nurserymen that it is a plant of exceptional character and beauty.

The dogwoods this year -- to transcend glooom -- have been exceptionally fine, as well they should, since last year they barley bloomed. Many woody plants are alternate-year bloomers. They have a virtual hemorrage of bloom, then the next year they barely bloom. They are recovering, as from a great binge.

Many crabapples, and indeed some apples, are alternate-year flowerers. So are some nut trees, so are some beeches and oaks and so forth. But there are plenty of other plants that are not alternate-year producers at all, but all the same they take a year off from time to time. As I reckon it, they go along cranking out flowers and fruit year after year and then they have had it up to here, and take a year off.

My plum, Prunus blireana, has taken two years off in a row, which is overdoing it.

But the great thing about garden plants, and Nature in general, is that there is no point arguing or getting mad; there it is, and if you don't like it, try doing something about it.

Gardeners, of course, learn this lesson early. Often, however, people come to me accusingly and announce their roses are not doing this, that and the other, and the implication is clear: it's my fault.

And if a moon vine, oak, trumpet vine, grape or nasturtium should die somewhere, I am almost certain to hear of it, and I have never known whether I am supposed to resurrect it or to apologize for my wickedness in allowing it to die in the first place.

Another thing people reproach me with is the failure of lilacs, peonies, irises or whatnot to bloom throughout the year.

"You mean they only bloom a few days once a year?" is the incredulous beginning of the complaint.

It is not what I mean -- I have nothing to do with it -- it's the way things are, and there is no way I or anybody else can make peonies, say, bloom four months in a row.

People who do not understand how hard Nature is are invariably astonished to learn that hardly anything in the garden blooms more than a few days a year. They cannot believe, at first, that any sane human would take care of plant 12 months a year for a mere five days of flowering.

Then they go on a trip somewhere and see some great garden on May 10 and come home all fired up at what they've seen. They have lists of wonderful plants new to them. They suppose, in their innocence, that the climate there (wherever they saw the garden looking glorious) is so different from ours that plants bloom perpetually there. And when they are told (at that garden) that they could grow the plants they so much admired right here in Washington, the come home ecstatic, until they discover they can't get the effect of a 20-year-old skimmia in a year or two, or discover the vast labor involved in training a rose like 'Mme. Alfred Carriere' around second-story windows, etc.

They cannot believe anybody would take that much time and sweat to achieve the effect they admittedly admired greatly.

Fortunately for me, my own garden has nothing of the slightest interest in it, but owners of fine gardens know all too well the common back-handed praise: i

"Just look at those huge tree peonies, they just grow for you like weeds. Of course, everything does. You are lucky. For me those tree peonies never get off the ground. I imagine you have more shelter here. Etc. etc."

The gardener with the amazing lilies or tree peonies or whatnot has usually gone to unbelieveable labor or expense or both to provide two solid feet of leaf mould mixed with sandy loam, etc., and that gardener is not usually very flattered to have his triumph dismissed by "Of course everything grows for you, because you have better soil, shelter and so on."

The new gardener usually turns into a true gardener the first time some plant performs exceptionally well for him, and then, a few years later, does not do so well. The memory of its original beauty haunts him, and he starts trying to recapture it.

The impetus to gardening, as to almost every other accomplishment, is success, however accidental and however brief. There has to be this shove, this free gift of temporary triumph, and then the gardener is willing to accept the drudgery, the terrible weather, the many disasters.

I always think nasturtiums are good to start with. They are as beautiful as any flower upon earth, and yet failure with them is exceptionally rare. Yes, the nasturium is one of the greatest plants, partly because so many gardeners find their first grand success with it. After which, of course, the fat is in the fire, and the ways of Nature do not seem so terrible.