May is magical for irises

You might call May iris time. That is when the classic bearded irises are waving their flags in irresistible, velvety, jewel colors. Bearded irises along with peonies form the backbone of a remarkably beautiful season in the perennial border, short-lived though it may be.

The iris is lumped, along with a few other perennials, into a derogatory category called "two- week wonders." They put on quite the display for about two weeks, and then you have the other 50 to stare at bare ground or bedraggled foliage. But the genus iris has about 300 species in it, and those who love their flowers have been enjoying them since mid-winter.

That is when the little bulbous iris -- the deep, blue-purple reticulated and the yellow Iris danfordiae begin to bloom. They are among the earliest flowers we see in the garden, often preceding the crocus. You would not confuse the little flowers of either of these with a bearded iris -- three of their flowers could sit neatly on one petal of a bearded iris.

Reticulated iris is planted in the fall. Each little bulb is covered in a net-like tunic, which is what reticulated means. It takes a lot of these little irises to make an impression, because they are only a few inches tall. After blooming, the foliage shoots up to about a foot, something that can be a bit of a surprise when you are planning for a 4-to-6-inch tall flower. The Danford iris behaves much the same way, though its flower is quite different and pale lemon colored.

The miniature bearded iris is next in line to bloom. These are just like the bearded iris we enjoy in May but shrunken to about 8 inches tall. Several of these will bloom again in the fall, and several are nicely fragrant. We won't bother with the names and colors of these, because there are as many here as in the tall bearded iris, a flower that, after all, was named for the Greek goddess of the rainbow.

The progression of bearded iris growth generally goes from smallest to tallest: miniature-dwarf bearded, standard-dwarf bearded, intermediate bearded, and then the big flush of border bearded, miniature-tall bearded and tall bearded. All of them spring from rhizomes - fattened roots that creep about near the surface of the soil and produce fans of foliage.

Bearded iris are easy to grow in full-sun conditions. Plant them in early spring or preferably late summer, giving the rhizome a chance to get well established before cold weather. They are tough plants and benefit from division every few years after the foliage dies back. Replant the rhizome so that it is visible at the surface.

Just after the earliest miniature iris, the beautiful native crested iris has its fleeting moment in the sun. The sky-blue flowers of the dwarf-crested iris are woodland gems, and the grassy, fan-shaped leaves are a nice contrast to the many round and heart-shaped leaves of other wildflowers. Only a few inches off the soil surface, the flowers of the dwarf crested iris appear nestled down in the foliage.

Right at about the middle of the bearded-iris blooming season comes the Siberian iris, a much daintier flower than the bearded, which can sometimes give the impression of a double-dip ice cream cone. Siberian iris flowers are smaller and more open, and their leaves are thin and grass-like. While the fan-shaped foliage of the bearded iris tends to fall apart in mid-summer, the leaves of Siberian iris persist and contribute in the garden.

Dutch iris follows with tall slender leaves and big open flowers of deep purple or yellow. Like the little reticulated irises that began the season, the Dutch irises arise from bulbs planted in the fall. They are often encountered in the cut-flower trade. They may not last very long in the garden but are worth replanting for their beautiful sculptural flowers every year.

Japanese irises are the heralds of the end of the iris season, and in many respects the best have been saved for last. Japanese iris loves the moist soil found at pond's edge but will perform in all but dry shade. Japanese iris are almost all "fall"-- the petals which droop downward -- and very little "standard" -- the upward-pointing petals that form a bowl in the bearded iris. They can grow to three feet tall. The yellow swamp iris that is often seen in wetlands is related to the Japanese iris and is called Iris pseudoacorus.

There are other irises that the connoisseur can seek out, each exotic enough to live up to its nickname, Poor Man's Orchid. Each stretches the season beyond that magical two weeks.

-- If you have a gardening question or story idea, write to David Bare in care of Features, Winston-Salem Journal, P.O. Box 3159, Winston-Salem, NC 27101-3159, or send e-mail to his attention to gardening@wsjournal.com.