Almost everyone grows a tall bearded iris. Those who class it as one of their favorite flowers have often lamented that its season is too short. Would you believe me if I told you that I had had some form of the iris in bloom in my Denver garden for ten months of the year?
This is true, although it is also true that I have had to use many forms other than tall bearded irises to get this result and that this does not happen every year but only some years.
Early Birds
One of the grandest surprises you can prepare for yourself is to arrange to go out on a snowy February morning and find fragrant snippets of purple poking up through the snow. You will get this reward if you put the bulbs of Iris reticulata in the ground the preceding fall.
These little darlings last for years once planted and do well even in climates where winters alternate from sunny and fair to below-freezing, as they do here in Colorado.
For February bloom, put them in a sheltered place south of a wall. Put another group of them somewhere that is not sheltered, and after the February bloom is gone, you will have some more in March. They like any soil with good drainage.
The careless passersby who do not look at them closely often think they are crocuses, and for garden purposes, they can be used the same way, although we would not advise putting them on a lawn. Use them at the edge of beds and borders, or try them in rock gardens.
The next rock garden and border iris that comes close on the heels of reticulata is the dwarf bearded. Careful planning with these brings bloom from late March to the end of May. The earliest is the stemless pupils and their hybrids.
An old reliable always in color for us at Easter is ‘Atroviolacea,’ a pumila hybrid. Start with a plant or two in a vigorous condition and be prepared for mats of purple bloom after a few years.
From mid-April to mid-May, many faithful pumila hybrids bloom in our garden. If you like pansies, you will like this doll-size iris.
Do not expect these brave ones to be as large and showy as their tall relatives; remember that they must snuggle down away from the chill breezes and uncertain weather of early spring.
Somewhat larger, later, and less expensive are the older dwarf bearded irises with more Iris Chamaeiris in their ancestry.
Those charmed by the pumila group often find this latter group too large and coarse for their taste, yet it fills an otherwise blank spot in the season. These are especially useful in spring rock gardens.
Among the newest comers to the iris world is the Lilliputs. The American Iris Society classes them with the standard dwarfs, as they are smaller and of daintier form than the intermediates.
Yet, as they are hybrids between tall and dwarf bearded, they tend to be larger and later than true dwarfs.
The older, more significant intermediates (usually crosses of Chamaeiris and tall bearded irises though some have other pedigrees) were favorites in our grandmothers’ gardens, and many are still popular as harbingers of the tall bearded iris season.
Some even serve a double purpose by blooming twice. This is a wide-open field for hybridizers who want to produce something new and different, for until recently, not a lot had been done along this line for several years.
Oncobreds
In a class are those irises with oncocyclus or regelia blood mingled with pogoniris (bearded) ancestry.
The “oncos” and regelias also have beards but are different in so many ways that they are put in a separate category from the usually bearded irises. Their hybrids are traditionally easier to grow than the pure species.
While they may be part dwarf and bloom very early, most of them bloom at about the same time as the intermediates or a little later, at the beginning of the tall season and the tails.
Now, as we approach the height of bloom season, there is much overlapping of bloom times of the different iris species and varieties. Some of the beardless, rhizomatous kinds will bloom before the tall bearded, others at the same time, and still others come along after the tails are through.
Therefore, let us consider the beardless, rhizomatous group as much for their particular needs and landscape uses as for their bloom times.
Beardless Kinds
Their most significant value is for the poolside and water gardens. The Siberians, spurias, and Iris missouriensis (the most widespread American native iris found throughout the West) can tolerate drier conditions than most of the plants in this group but need plenty of water before blooming.
They can be planted farther from the water source in slightly higher, better-drained locations than the others. They also bloom earlier. Some Louisiana irises will bloom before the tails are through but will lengthen the season by continuing into July in Northern climates.
Unless you live in an area where the Louisianas grow wild, you should hesitate to try the newest named hybrids until the experts in your area have proven them.
For your first experiments, stick to the tried varieties that have been hardy throughout the country for a number of years.
The spuria, or “butterfly,” irises require little in the way of particular soil or attention. They may provide a background accent since they usually become taller than Siberian or tall bearded, and the handsome, disease-resisting foliage is an asset throughout the season.
Spurious bloom after the tall bearded; the time interval between them is more significant in Northern states.
Don’t forget that most of the beardless, rhizomatous irises are like a thick blanket of mulch, and while they should not be planted in the water, it is well to have them near enough to your pool or irrigation ditch to take advantage of any flooding.
If you lack these sources, don’t fail to rinse them with the garden hose, especially early in the season.
The gorgeous Japanese irises can be grown in an area where the soil is predominantly alkaline. Provided you want them badly enough, give them a bed filled with good soil containing much organic matter and annual treatments of sulfate to keep the balance on the acid side.
These irises not only bloom after the tails are all through, but they are so spectacular that whether you mass them behind your pool for landscape effect or float a single bloom in a bowl, you will draw excellent comments from all who see them.
If you do not have a pool or a creek, select the lowest, most poorly drained spot in your garden and build a small, artificial swamp rich with organic matter. Then pick out some of the older Japanese varieties.
Tall Beardeds
Now back to May, June, and the garden queens, the tall bearded irises. It is the rare garden. Indeed, that has not one of these.
But if the ones you are growing do not impress you very much or if you have only a week or two of bloom from them, perhaps you have not checked on the developments of the last ten or 20 years.
Do not select by color alone. Many catalogs state whether a variety tends to bloom early, mid-season, or late. By choosing a few of each, you can spread the bloom out over five or six weeks, with some starting in May (much earlier if you are in a warm climate).
Live where late frosts often nip things in the bud. It might be wise to forego the earlier varieties (although you can still try dwarfs and intermediates because of their different growing habits) and concentrate on those listed as midseason and late.
When your tall bearded irises are all through, and even the Japanese have come and gone, there may be a hot, mid-July lull when there is not a single iris in bloom, but who cares?
It is too hot to go out and look, anyway. Everything is taking a breathing spell except the lawn and the daylilies.
Vesper Iris
But toward the end of July, if you have planted Iris dichotoma, you are in for a new thrill. Dichototna is also known as the vesper iris, for it does not bloom all day long but waits until late afternoon.
Go out about three-thirty or four in the afternoon and watch the branches closely – don’t look away! You might miss the fun.
You will be startled when exotic little orchid-spotted blooms pop open into flat-petaled wonders like bubbles bursting. They stay open until the sunlight of the next day. They will keep this up every day until the end of August.
They are not long-lived, although they are not biennials, as some think but will often last for several years. They are quickly started from seeds and will come up. as volunteers from fallen sources.
We must admit that fall blooming irises are a sometimes thing, depending very much on climate. If you have early fall freezes, it may not be worthwhile to try them unless the freezes are pretty light.
Yet even here in Colorado, where we sometimes have frozen as early as the first week in September, a few fall bloomers have been quite faithful and have been known to bloom from the end of September until early November.
Even if these don’t bloom in the fall, they are sure to have bloomed in the spring, and their occasional fall surprises make them worth the space they occupy. They may give more in the fall if they have been prevented from blooming or setting seeds in the spring.
Extra water and food may also help to ensure a crop of blossoms in the fall. If you want to experiment with remontant or fall-blooming irises, it is well to select plants that were developed in your area.
Many of the irises that grow and bloom in the winter in California are unreliable, even as summer bloomers in the rest of the country.
Nor is it likely that many of the unusual species which are reported as December and January bloomers along the Pacific Coast can be counted on to survive in the rest of the country.
If you must try such things as Iris stylosa (unguicularis is the preferred scientific but less euphonious name), then try them in pots in the house, but don’t count on them to bloom.
If you have an iris in bloom for from six to ten months of the year, perhaps your iris calendar is full enough, and you and your iris can take a rest for the remaining months of the year!
By L. Housley
13828 by NA