The Japanese iris always reminds me of the Chinese tree peony -- a flower to examine one by one, and worthless in the landscape.

In the landscape you need things like fruit trees, mass-flowering climbing roses, viburnums and kerrias, azaleas and California poppies, things that have great impact when viewed from a distance.

The Japanese iris is a flower to examine inch by inch, up close. It is a perfect flower for the connoisseur, alone in a small courtyard.

All the same, and never mind exquisite taste, it is also a fine flower for anybody who thinks nothing can be too gaudy, too overstated, too imperial. I have known rednecks who adored it.

It blooms after the tall bearded irises, the ordinary garden irises that I think are the most beautiful of all flowers. The Japanese iris blooms in June around here, and in July in many places to the north.

Thirty years ago I bought a number of these irises of the Marhigo strain at a price then considered very high indeed. I did this because they were supposed to have better substance, better texture, better resistance to heat and rain, zub, zub, zub.

I did not perceive they were any better than the old varieties imported from Japan that everybody used to grow. Then one year I bought a packet of seed from Park's, and found the resulting flowers as good as the quite costly ones I had indulged in.

I saw, not for the first time, that breeders are like ordinary gardeners -- they think their seedlings are superior. Any breeder who cannot see vastly improved substance, texture etc. in his productions has no business being a breeder. But the common gardener frequently fails to see that 'Pearl of the Hummingbird's Tail' is any better than a Japanese iris raised from mongrel seed. Possibly one pays for the imagination that went into the name.

For all that, the Japanese iris remains one of the few garden flowers that I myself would apply the adjective "gorgeous" to.

It requires, and needless to say deserves, quite rich soil in full sun; the best spot in the garden. There should be plenty of humus and plenty of old rotted manure, and an endless supply of water. The soil should be acid, a requirement easily managed in this capital.

The rhizomes are surprisingly small, compared with ordinary garden irises. They do not seem large enough for an iris borer to inhabit, but it is a sad truth: The iris borer will drill down the fan of leaves and take up residence even in Japanese and Siberian irises. I lost a whole batch of both.

There are systemic poisons that are said to be pretty effective against this disgusting pest, but as I will not use them, I am in trouble.

No doubt a careful gardener with a sharp eye can catch the borers before they chew down through the fan of leaves. It is sometimes said that a mulch of wood chips makes life hard for the borer. Others say gravel discourages them. Others say a weedy garden discourages them. Others say meticulous cultivation, with absolutely no weeds at all, is the way to go.

The plants are easily (not all that easily, come to think of it) divided and moved (and shipped from nurseries) in May and June. An important thing is to keep the new plants, which have their leaves greatly trimmed back, distinctly damp.

If new Japanese irises are treated like tall bearded irises -- watered in when planted, then left to grow on their own -- many or most of them will die. Unlike bearded irises, which come from Europe and Asia Minor, where they dry out in summer, the Japanese iris comes from damp meadows or actual swampy land in Japan, China, Siberia and Korea.

Or so I have read in "The Japanese Iris" by Currier McEwen (new from University Press of New England, $30), which is a long time coming and which is the first book on this glorious garden flower that I have ever found.

For some reason Westerners like to think everything from Japan and China is unspeakably ancient. With this iris, there is no doubt that for several centuries now the Japanese have selected variations, and especially within the last century or so have consciously bred this iris for endless variations in color and pattern.

My own favorites are the ones with three large petals, the falls, and three small upright segments, the standards, and this sort is called "single." In other varieties the standards are greatly or grossly magnified to the size of falls, and all six segments flare horizontally or hang down.

I have never cared for the ones that hang down, but I admit the hanging petals display the intricate patterning well. Some of the Japanese irises are more or less solid colors, but most of them have standards one color and falls another. Furthermore, the basic color of the large petals is often veined in an intricate and irresistible way. Mulberry rose veined with gold, or white veined with blue; or dark purple veined with gray, and often with a yellow dart near the base.

Oh, there is no doubt that even the ones I like least are beautiful almost beyond description and certainly beyond nitpicking. They deserve a bed to themselves. Theoretically they can be grown in a mixed border, and I have seen them successfully treated that way. But I would never grow them thus. No, a bed, which could be as small as four feet square, all to themselves is much better. It can be deeply dug, down to 14 inches if strength holds out, with plenty of old manure and leaf mold. And near a source of water.

I have read accounts of gardeners who say the best Japanese irises they ever grew were at the top of a sunny bank that baked in summer. I simply do not believe it. Or perhaps it was some miracle that happened once and a long time ago. These irises like water; an inch and a half or two inches a week all summer is by no means too much.

It may be that as one approaches the North Pole they like to be dry in winter, but in civilized regions of the world I believe they do not like to be dry even in winter.

How often I think of people with tiny sunny gardens, no larger than a living room, and think how much pleasure they would get from these irises, which can even be grown in pots and set a couple of inches beneath the surface of a small garden pool as they come into bloom.

This is one of the greatest and most spectacular flowers, as large as a saucer or a salad plate. Quite vulgar, actually. But there is a point beyond which vulgarity becomes magnificence, and the Japanese iris found it ages ago.