Iris means rainbow, and no other flower deserves this name quite well. You will find masses of all spectrum colors among the tall bearded irises.
Add elegant flower form and texture, plus a hardy disposition that lets the plant live almost everywhere, and you have a spectacular garden perennial.
It fails only in the deep South, where winter temperatures never drop below 20° degrees Fahrenheit. Other iris groups spread the blooming season over a long span.
Tall bearded kinds, reaching a peak in May and June, provide the most color and the widest variety. A few kinds will sometimes bloom lightly again in fall.
Before this, you have had color from the fragrant netted iris (Iris reticulata), which came into flower with the scillas; the dwarf irises, which bloom with species tulips; the median, table, or intermediate irises, which are halfway in size and season between dwarfs and tails.
As the tall bearded flowers taper off, Siberian irises’ slender purple or white buds open. Next are the spurias, usually white and yellow (but not always), and considerably larger, and like the Siberians, beardless.
Finally, the last strong note of the iris season is sounded by the Japanese irises (Iris kaempferi) opening magnificent blue, white, orchid, and purple flowers in late June and July.
Scattered through the season are flowers from others of this numerous group—the cristata or crested iris; the tectonic or roof iris; the Louisiana iris; and later in summer, the afternoon-blooming vesper iris (Iris dichotoma).
Iris Companions
You can use irises all alone or mixed with other plants. When you have a large collection, it’s best to give them space alone. While they are blooming, they make a show that stops traffic.
The rest of the year, the plants are just there. You may prefer to grow irises among other flowers. The spear-like leaves make good accents in a mixed planting, so you get some good out of irises even when they are not blooming.
Start with the tall bearded irises. Here you can select from hundreds of good varieties. They come in sizes from 15” to 40” inches high, and the catalogs rate their blooming times as early, midseason, and late.
Look for Dykes Medal winners (an award the American Iris Society gives to truly superior varieties). You can’t go wrong with any of them.
Plant tall bearded irises in the sun, where the ground drains well. They can stand baking in the summertime. Plant rhizomes so the root sits flat under the soil, and the white roots extend out and down.
After three or four years, clumps become crowded. When flowers seem smaller or fewer, the roots need to be divided. Do this right after blooming time.
Dig the clump, break off the husky outer rhizomes topped with big foliage fans, and save them for re-planting. Throw the rest away.
How To Grow Siberian Irises
Siberian irises need more moisture and shade than tall beards but don’t put them in deep shade. Their roots are fibrous. They can be transplanted at any time, even while blooming. Once you’ve planted them, leave them alone.
They need little attention except dividing when clumps get overgrown every four or five years.
Erect and stately, with fine foliage and slender stems—each crowned with a few perfect small, beardless iris flowers of purple, blue, or white —these make good accents among other plants. They average 30” inches when in bloom, so place them halfway back in the bed.
Spuria irises resemble Siberians, but they are taller, stiffer, and have no fountain of foliage at the base. They may grow 5’ feet tall. The flowers are large and flaring, wonderful for bouquets, and usually in white, yellow, and light blue colors.
Place spurias toward the back of plantings and where there’s moisture—a good kind: ochroleuea gigantea, beardless with yellow and white falls and standards.
Japanese Irises Have Splendor
Japanese irises have pretty flowers, unlike any other irises. They are flat and wide, perhaps 8″ inches across, without a trace of beard but often waved or ruffled. They sit atop 3′ foot stems.
Colors are in the white-orchid mauve-blue-purple range. This is because plants need more humus and soil acidity than other irises and more moisture at certain times.
Water them copiously in spring and summer, but in winter, see that they’re well-drained and well-mulched. Plant or divide any time after flowering. Try any of the Oregon-bred kinds called Marhigos.
44659 by Rachel Snyder