Have you wanted to know more about the ancestors and cousins of the popular tall bearded iris?
One way to satisfy the yearning for more irises and simultaneously gain the answers to your scientific curiosity is to grow some of the iris species—the original plants from nature, untouched by human hybridizers.
It is often thought that our high dry plains are not too unlike the dry areas that are the native home of the Oncocyclus group of irises from the Holy Land.
Perhaps this is the only species suitable for growing on the western prairies. It does not work out this way.
Ancestral Homes Of The Oncocyclus
The ancestral homes of the Oncocyclus, from Lebanon and Palestine to Persia, are hotter than our plains and mostly at a lower altitude.
Unless you happen to choose a tougher species from the mountain regions, many of the Oncocyclus group are not reliably hardy in our region and even pass on some of their tenderness to their hybrid offspring.
If you live in an area of late spring freezes or summer rains and love the fat form and wide, hairy beards of the Oncocyclus, it is best not to try to grow such species as Gatesii.
Choose Iris Hybrids
Rather, choose hybrids that have been bred from these with the hardier tall bearded iris for a few generations, such as the always popular ‘Elmohr’ and ‘Lady Mohr.’
Even with these, it is wise to remember their ancestry and put them—no, not in a sheltered location—but in an exposed spot where they will not form their buds too early and get nipped by a late freeze.
Nor should they have much water in late summer when it is time for them to rest a while and soak up the sunshine.
Growing An Oncocyclus Species
If you have your heart set on growing an Oncocyclus iris species, try Susiana. Relatively inexpensive, this can be grown and bloomed by those willing to take a little extra trouble to study its needs.
The primary need for drainage and summer baking is perhaps more easily met in Colorado than in the states to the east, where there may be more summer rains.
Close relatives of the “Oncos” are the slimmer-bloomed Regelias, who are said to be a little easier to grow than the “Oncos.”
We have not found them so, however, because of that same tendency to make their buds just in time for a late freeze.
If you are willing to risk this for the sake of having something unusual, try such varieties as ‘Korolkowii Pink’ or the stolonifera registered as ‘Decorated Delight.’
Kinds Of Dwarfs
For early bloom, the safest things to use are the dwarf bearded iris kinds, which keep their bloom nestled close to the ground away from cold winds.
In a few years, a few plants will give bloom cushions in rock gardens and borders from Easter until May Day.
The older, taller dwarfs bloom later, but in recent years, a few enthusiasts have imported and hybridized with the pumila species, developing a wonderful new line of dwarf hybrids.
‘Carpathia,’ ‘Nana,’ and ‘Sulina’ are all named selections from this petite species worth growing. Other dwarf species to try are I. mellita, I. Attica, and I. Arenaria.
Ancestors Of The Tall-Bearded Irises
Ancestors of the tall-bearded irises that are of interest and hardy in our region include I. pallida, very commonly known in this area as “the old grape iris,” and Iris pallida variegata.
Don’t overlook the beardless irises for something different for arrangements and to extend your season beyond that of the tall bearded.
They have been favorite subjects of great artists and flower arrangers for generations, and most of them are hardy almost anywhere.
Beardless
In the beardless, rhizomatous group are:
- The Siberians
- Spurias
- Louisianas
- Japanese (which are not true species, mingling the “blood” of both Iris Kaempferi and Iris laevigata)
- Iris versicolor
- Iris prismatica
- Our native iris, Missourians (which takes its name from the Missouri river and is found in a wild state throughout the entire West)
Requirements of this Group
All in this group like moisture, though prismatica and Missourians can be grown in a rock garden, provided it is not dry.
The ideal location for most of these is at varying distances from 3 small pools or in a low, marshy spot. However, they can be grown in a perennial border, provided you water them as often as you do your lawn and flood them occasionally before bloom time.
They need not be in full shade if they are kept thickly mulched. Their requirements are the opposite of the bearded iris, which likes sun, drainage, and clean feet.
The beardless need to keep their rhizomes cool and moist and do very well if you provide them with organic food.
If your soil is alkaline, give the beardless at least an annual dressing of iron sulfate to acidify the soil and prevent the plants from becoming chlorotic.
Louisiana Species
Have you thought that you didn’t dare try any of the native Louisiana irises (a complex of about three species, also known as the Hexagona or Delta group) because you are in a locality of much winter snow?
Many of these will do well far from their native swamps and have grown as far north as Michigan, the Dakotas, and even into Canada.
The species include giganticaerulea, fulva, and foliosa; many good collected clones are available. They grow readily from seed, but the seed must not be permitted to dry out.
The Popularity Of Siberian Irises
Siberian irises are popular everywhere but, for the most part, are named varieties and hybrids of Iris Orientalis and Iris siberica.
Other beardless irises which do not grow from rhizomes but from bulbs include those popularly known as “Dutch” iris—though their ancestral homes are in the mountains of Southwest Europe.
Most of the named varieties are forms of Iris xiphium, though the popular ‘Wedgwood’ also carries the blood of Iris tingitana, a related species.
English Irises
Close relatives of the “Dutch” are the so-called “English” — Iris xiphioides — but we cannot recommend that these latter be grown on the high plains by any but the most ardent fancier.
Their blooms are beautiful, and if you want to invest the time and trouble—the cash outlay is small—be prepared to put the bulbs in the ground, then never see a plant or a bloom.
They like moist soil more than the Dutch, which requires some drainage and will grow in the borders of the bearded irises.
The Dutch are reliably hardy and will last several years. However, the English may not live through the first winter that you plant them.
Bulbous Iris Reticulata
A tiny relative of theirs, the bulbous Iris reticulata, will live through many winters. In a sheltered location.
It will bloom in the winter, putting up bits of purple velvet through the snow in late February and early March, coming ahead of some of the crocus and companion to the tulip Kaufmanniana and the Christmas rose.
Easily found are the species type and the varieties ‘Hercules’ and ‘J. S. Dijt.’ A light blue species is Cantab, and Danfordiae is yellow. The latter also makes a delightful winter window garden subject.
Crested Group
We must not forget the crested group or Evansias. Most of these are exotics, not hardy on the high plains, but I. cristata, native to the Great Lakes region, and Iris tectorum, from the Orient, can be grown in our areas with some success.
The loveliest tectorum is the white form, alba, which does not have a long life span, but which can be kept going from seed.
In a class by itself is the July and August blooming iris dichotoma, or vesper iris. This, too, is readily grown from seed.
If you have a large curiosity bump and love the unusual, get off the beaten path!
Try a few iris species, no matter what you may have been told about the impossibility of growing them on our great Midwestern plains! And you open for yourself a jewel box of treasures.
44659 by Lys Housley