A FELLOW complains -- correctly -- that this column yaps so often about plants and flowers that the garden itself is lost sight of.

You can't see the garden for the plants, so to speak. The fellow says, in effect, the plants are almost unimportant, and the great thing about a garden is for it to be peaceful and beautiful at all times, and that for this higher goal of serenity the gardener should deny himself knick-knacks (in the form of delightful plants) that only get in the way of garden beauty.

He is right, or almost right, or halfway right. Let me observe first that people who are generally ignorant of plants, ignorant of their incredible variety and beauty, naturally tend to believe the enormous area of their ignorance is unimportant.

If they know the yew, for example, that's good enough for them, and they go no farther down the road of conifers.

If a yew will do the job of providing a dark green conifer, they seem to believe, then why bother with junipers, cryptomerias, cunninghamias, curpessocyparuses, cypresses, arbor vitaes?

And if a yew will make a green blob (and I agree that the yew is not surpassed in beauty by anything), why waste any time or thought on other conifers, let alone other evergreens that are not conifers but which might also take the place of a yew. Such as hollies, leucothoes, evergreen viburnums, box, ivy, barberries, evergreen oaks, cherry laurels, photinias, nandinas, loropetalums, cleyeras, skimmias and so on.

And if the yew will do (they tend to go on), there is no need to think of other conifers, other broadleaf evergreens, or other evergreen herbaceous plants such as hellebores, yuccas, ruscus, epimediums.

If you want something green all year, in other words, you plant a big yew, a little yew or a very dwarf yew, and forget all the rest. So why (they wonder) all this babble about so many different sorts of plants, when yews all alone, in their different varieties, will do the job?

In answer (though not in argument, for there is nothing wrong with their argument that yews alone could serve the purpose) I have two or three things to say:

First, plants are valuable in a garden not merely for the purpose they serve in the design (providing the dark green shape) but are valuable in themselves, as individual objects of wonder.

Thus you will see that for all its merits the yew does not provide certain beauties found in all the plants thus far mentioned.

There is glory of the yew, admittedly, but there is also a glory of the cedar and another glory of the cunninghamia and all the others mentioned, each of which has certain beauties unique to itself, not duplicated in the yew.

Second, it is not all that true that a garden exists for the purpose of being beautiful to look at all the time, or for the purpose of being serene. A garden ought to be that, but a garden can be far more than that.

In addition to being a handsome picture, and in addition to being serene and restful and uncluttered and all those other good things that you keep hearing about (especially from people who do not know much about plants themselves), a garden may also be a treasury of life, a treasury of progress and a treasury of process.

A garden planted just with yews can be as beautiful as any garden needs to be, and can be far more beautiful than most gardens are.

And if the point of the garden were merely to be a lovely picture full of serenity, yews alone would do the trick. But suppose, as I argue here, the garden is also able to be a treasury of progress and of process -- what would that mean?

Simply this: There is incredible richness to be found in the yearly progress (new leaves, old leaves, fruit, bark, changing color, changing texture) in a thousand plants besides the yew.

This vast richness is not to be found in a garden of yews alone.

Simplicity is all very well and serenity is all very well.

But there is glory also in complexity.

Take music. Nothing is lovelier than a girl singing without any accompaniment some sweel old tune.

But because that is utterly wonderful does not mean that the sole glory of music is the girl singing the tune.

There is another glory of complex music, of fugues with many themes, and choirs of many parts, and oboes and harps and trumpets and cellos and horns. You cannot say, with any sense, that music becomes lost when you leave the girl singing the tune. Music may still be present, and present in very great glory, when it is complicated by entire choruses and orchestras.

Or take architecture. The Pyramids are as impressive as anthing, and nothing could be simpler, architecturally. They are a mere geometric shape, without any adornment or complexity at all. In their grand simplicity they are wonderful indeed.

But you cannot say, with any sense, that once you leave that simplicity of shape -- once you build something more complicated -- that you have therefore lost the true glory of architecture.

A building can be endlessly complicated, like the church of Chartres, and can be a "mish-mash" (as purists would say) of many styles, and still be a masterpiece of architecture, like Penshurst for example.

Or it can depart far from the Pyramids in simplicity, and boast mosaics and colored marbles and ornate sculptures in bronze and silver, and employ all sorts of subtle effects of lighting -- St. Marks in Venice, for example. a

You can travel far away indeed from the plain open satisfying simplicity of the Pyramids and still find great glory in architecture.

Only a fool or a yokel would complain of St. Marks that it is ruined by its endless colored stones, its forest of domes, its endless complexity of surface and volume, and urge that it would be better if it were shorn back into a geometric shape like a cube.

The Pyramids are beautiful, as magnificent as anything in all architecture, but there is not much there to pass your time as the years go by. aOnce you've seen their perfectly apparent glory, that's it.

You can spend a lifetime, however, exploring St. Marks, which has an infinity of nooks and crannies to investigate. The walls alone, with their endless mosaics, can keep you busy for years, and so can the astonishing collections of rare marbles, collected from the whole ancient world.

There is danger, of course, that a forest will be obscured by the trees, and there is danger St. Marks will be overwhelmed by the richness of its ornaments. I can only say that for me it is not damaged in the least by its endless complexity and profusion, any more than a F Major Fugue is damaged by its complexity and ornament, even though it is very far from the simple tune sung by a girl.

In gardens the same thing holds true. The plainest design, with the plainest and most sparse assortment of plants, can be wonderful as the simple Pyramids or the simple tune by the girl are wonderful.

But a garden can also be like St. Marks, with endless variety and richness and luxuriance and profusion.

For purposes of a two-hour visit, the Pyramids are at least the equal of St. Marks. For a five-minute hearing, the girl with the tune is at least equal to the Fugue in F.

But we are simians, and we soon enough tire of simple abstractions. We like to poke about and explore. We like many surfaces, many lights, many textures, many patterns.

A simian will always prefer St. Marks to the Pyramids if he has to spend 50 years with only one or the other.

In the same way a very simple garden all of yews is very fine, nothing is finer, except for this: It has not the richness, it has not the variety, it has not the tension, of a garden full of endless other plants.

Somewhere along the line, of course, richness and complexity must stop, else there will be chaos. But is the fugue chaos, is St. Marks chaos? sI don't think so, even though they are loaded with ornament and are made of endless numbers of parts.

Complexity and richness can go very far indeed before destroying the overall beauty of a building or a piece of music or a garden.

And the more you love a thing, the more you are likely to want it in its greatest richness, its greatest complexity, its greatest excitement and tension.

Of course if you're afraid of vulgarity (and the Lord knows we all have endless reserves of it) you can play safe by designing only a Pyramid, or only a garden of yews. Then you can never be accused of anything extravagant or foolish.

You will always have unity, repeated rhythm, surfaces that do not conflict or jar. You will have serenity, the absence of clutter.

But you will not have the little cones of the cunninghamia, the little flaring fountains of ruscus, the tender salmon spring leaves of andromedas, the somber massive fruits of photinia, the green burgeoning of hellebores in February, the gradual purpling of junipers in November, the bronze smolder of leucothoes in winter.

The true danger to the joy of gardening is not really that gardeners grow too many plants or lust too strongly for variety and richness.

But the other way round: we settle for too little. We do not explore enough. We do not reach out enough.

We settle for harmonies too simple to satisfy us over the long haul. We accept contrasts too trite to delight us. We are too timid, too weak to risk failures with untried plants, and we cannot laugh and start all over when something we had counted on proves ridiculous in reality (though it looked great when we first thought of it in our minds).

So we play it too safe, limiting ourselves to what we know will always work -- the row of yews, the blue irises with the pink peonies, the larkspurs with the Madonna lilies, the plain grass like a wonderful green carpet.

Those are all great things, but they are not everything. The joy of some rare alpine, or for that matter the gorgeousness of some great robust weed: these are also substantial and legitimate joys in gardening, however incidental and unnoticed by one who takes in a garden at a glance, not living in it year after year.

Whatever the sins of the column may be, the undue celebration of simplicity is not one of them. Let a thousand flowers bloom. The dangers of chaos are no worse than the dangers of timidity, and the sin of extravagant gaudiness is no worse than the sin of prim correctness. There are worse epitaphs for a gardener than that he was bowled over by everything he saw and wanted everything there is.