CLEMATIS MAY be planted in March in a sunny place (but well shaded at their roots by a shrub or stone) and there are only two problems:

Which, among dozens of sorts, to choose.

How to make the dratted things grow.

The first problem, which kinds are most beautiful, may be glossed over, since they are all pretty glorious, but the second question -- how best to grow them -- will require several minutes of effort on the gardener's part.

It should be said, though without any intention of adding to the world's already adequate store of guilt, that the average gardener is suprisingly lazy and, not to split hairs about it, pigheaded.

Every book in Christendom says ground should be "well-prepared" or "well-dug" or "in good heart" or "well-drained" and "reasonably full of humus."

The gardener, therefore, having though about these things all winter, leaps forth in March, about the time the very first daffodils are blooming, to chop a hole the size of a coffee can in some godforsaken spot encumbered with couch grass (since it is easier to dig where coarse grasses abound) and plops in his clematis or rose or what-not, and sits back to await the promised splendor.

The usual cause of failure with clematis, or anything else in the garden, is slovenly planting. In my own case (perhaps more tactful than considering yours) I have rarely lost a plant that I really wanted sufficiently to prepare a reasonable spot for it to grow in.

A place the size of a bushel basket, dug 20 inches deep and filled with good garden soil will do. Good garden soil is as follows:

It is whatever soil you have, to which two heaping shovels full of peat moss, one shove full of sand and one or two shovels full of leaf mould have been added. By "added," I mean that in this spot for the small clematis plant, you dig in the things I have mentioned until the mixture is quite uniform for a depth of 18 inches of so.

This is watered, allowed to settle and when it is dry, it is firmed down with the feet. Then, after a few weeks, you plant the clematis there.

"It's too wet to dig all that in," the gardener says.

Which is why you are constantly advised to do it in October.

" I wasn't thinking of clematis in October."

Well, why not?

In March, therefore, you do as well as you can, and set the crown of the young clematis (which comes in a small pot or plastic bag) with the crown two inches below the soil surface.

The crown is the point at which the roots spring out from the main stem. Thus two inches of the main stem are under ground.

I find it helps to put a couple of bricks on top of the gound over the roots. The edge of the flat brick touches the stem. This helps a little in keeping the soil over the roots moist and even in temperature, and also reminds the gardener not to dig another little hole there and stick in a hollyhock. Many clematis are lost through failure of the gardener to remember exactly where he planted them.

Slugs and cutworms and, I suppose, other monsters like to chew off the tender shoots of the clematis as it sprouts in April. Do not let them do this. Once the plant is a couple of years old an soundly woody, there will be no great danger, but the first year put a device (a coffee can with both ends out) around the clematis to discourage dragons from coming in.

At the time of planting, set in a slender stick or other device for the young vine to climb on. The clematis twines. It does not like to flop on the ground.

If the aim is for the clematis to cover a post, them give the post some wires. Do not expect the clematis to wrap itself around the post without assistance. A strip of wire fencing (painted to match the post -- all this done last fall, of course) can be nailed flat to the wood post and the clematis will romp right up it.

I say romp. But often the clematis straggles up for three feet and then sits. The gardener is annoyed, his head being full of visions of total luxuriance. And it is just here than many clematis are lost:

Do not be in any way discouraged. Keep weeds away from the young vine, even if it makes only a few inches of growth the first year.

"It will be a century at this rate," the gardener commonly says, when his new clematis ceases growth in May and just sits there week after week.

It is unbelievable that a clematis that grew hardly at all the first year can grow eight or 10 feet the second. Covered with flowers.

New there is the matter of clematis wilt.

This is a disease that can carry off a clematis plant in the matter of a few days and it is, needless to say, the strongest argument against divine providence I can think of.

Some put their faith in benomyl sprays and drenches. But it would be sheer perversity to worry so much about wilt (from which the clematis often recovers if you do absolutely nothing) as to forego the pleasure of growing these happy vines.

Let me say there are only three kinds of clematis as far as I am concerned: the ones that bloom early, with wisteria and tulips; the ones that bloom with irises and roses and into the summer (and many of them tend to rebloom a bit in late summer or early fall); and the ones that bloom around Labor Day.

Of the first batch, the early ones, we have C. montana in various kinds. The pink montana is the easiest to find, but there are garden forms and hybrids too, such as 'Elizabeth' and 'Tetra Rose.' There are allied early pink clematis -- C. spooneri, C. vedrariensis, C. chrysocoma.

There is not as much difference among them as you might think from reading the passionate comments of clematis nuts. C. vedrariensis is the most beautiful, without splitting hairs, and I do not know where it can be bought. Once I saw a good collection of these early pinks at kew, in London, and asked myself if C, montana rubens was so overshadowed in beauty that I would not want it: The answer was no. It is not quite so lovely as C. vedrariensis, but there is not really much to choose.

Then of the warm-weather clematis, the ones with flowers like saucers, there are several dozen kinds in commerce, in white (like 'Henryii'), purple ('Jackmanii Superba') or pinkish-rose-lilac ('Comtesse de Bouchaud') and winy mahogany red ('Ernest Mark-ham') or whitish with rosy-wine stripe ('Nelly moser') and so on. Some of them, like 'Lady Betty Balfour,' bloom in late June and early July, when its rich blue-purple contrasts handsomely with day lilies. Some hot-weather sorts like C. tangutica (yellow) are small and urn-shaped.

The end-of-summer sorts are summed up with C. paniculata which grows all oever the place and seeds itself, about, producing almond-scented inch-wide white stars in tremendous quantites, falling like a white weil over fences, garages, old stumps, etc.

Christopher Lloyd's book, "Clematis" is the best I have run into.

At the Chelsea show in London in May you can see a rare plently of clematis in bloom, including many uncommon kinds not generally to be had here, but there is no need to be heartsick since the garden effect of such old kind as 'Jackmanii' is fine enough. The crying need, in my view, is for C. vedrariensis to be raised by our nurseries.

There is a garden in Ireland where the common blue wisteria, the yellow Banksian rose and this pink clematis all flower together in great masses against a monumental background of gray stone.

Too often we ignore the garden value of these wonderful vines.