It seems strange that the beautiful iris of the Pacific Coast is so little used in gardens elsewhere.
They are perhaps the most misunderstood beauties of our time, for they seem reluctant in Eastern gardens.
They are not rivals of the tall German iris in culture or form, although they can be colorful and striking plants for foreground use in a border conditioned adequately for them.
In size, Pacific iris ranks close to Iris pumila, but carries an airy grace unknown to these stiffer forms.
Proper Pacific Iris Growing Conditions
All Pacific iris cannot be treated in the same manner. Some, like Iris tenuis, grow in the dense coniferous shade on rocky river bottoms.
Others climb sandy slopes to peaty alpine meadows, and some irises grow in leaf soil beneath deciduous trees.
In general, it seems best to give them half shade and considerable moisture through their blooming period at least, though drainage should, of course, be good.
Most of them detest lime. Instead, sandy, peaty soil or one with leaf mold seems to please most of them.
A place where either rhododendrons or primroses prosper seems much more suitable than the borders made for bearded iris or the very sunny poolsides where the Japanese iris are in their element.
Pacific Iris Species
These western iris come with thick, leathery evergreen leaves and thin, grasslike ones.
Iris Tenax
Iris tenax, which seems to have made its way in gardens better than the others, has been aptly compared to a miniature Japanese iris on a 6-inch stem. However, this latter varies up to 12” inches, dependent upon the moisture received.
One of its greatest charms is the long blooming period and the many flowers it opens at one time.
This is an iris of decidedly variable color, more generally ranging from orchid-lavender to .purple, but an almost navy blue appears at times, and again a lemon yellow.
Bright lilac with purple veins and a variegated white and yellow spot in the throat is a frequent combination.
This can take the sun with ample moisture on the Pacific Coast but elsewhere.
I believe half shade is better. It has more of a brittle rhizome than do others of this wiry-rooted group.
Iris Gormani
Very similar in form is Iris gormani, about 8″ inches high, but with even narrower leaves and large soft yellow blooms that turn to cream with an orange blotch.
The culture is the same as Iris Tenax, except less sun. These both bloom in early summer.
Iris Innominata “Nameless Iris”
The most garden-willing and most satisfying in my experience is one hardly known— Iris innominata— even called “nameless.”
Nurseries seem to have ignored it, at least in catalogs upon my desk, but it may be had from English seed.
It, too, is a grassy-leaved species that comes easily from seed. Mine bloomed in 26 months from outdoor sowing in a seed flat.
They carried lovely lilac flowers, feathered with white and deeper shadings, on 9-inch stems.
Blue to deep lavender flowers have been reported, and there is a yellow form on the English market.
Treatment is the same as for Iris gormani.
Iris Macrosiphon “California Iris”
Somewhat similar in appearance to the last, though accepting a drier situation, is the foot-high Iris macrosiphon, also known as the California iris and Iris chrysophila.
This bears stiffer grassy leaves in a compact mass and large flat flowers varying from lemon yellow to white.
Iris Bracteata
Iris bracteata from the dry, open yellow pine forests of the Siskiyou Mountains is a cultural companion.
The evergreen leaves are leathery, and the dark yellow flowers are netted with brown.
Iris Tenuis
The wide foliaged, yellow-blotched, and white-striped purple Iris tenuis are among the heavy moisture-lovers of the more northern range.
This one responds remarkably to garden care.
Douglas Iris
The beautiful, hardy Douglas iris repays a little effort by giving long-season bloom and exquisite color variations in the huge flowers.
The dark blue to purplish ones are found nearer the ocean. But as they climb the mountains, they break into many colors—ivory splotched with gold, soft blue, mauve, violet, and straw color, veined with purple, often striped with white.
I have yet to meet a clear pink, but I have been so often told of one it must exist. It is a gamble for those who like to experiment with seeds.
Hardy Pacific Iris
I believe all these Pacific iris adapt themselves to gardens away from the front of their native conditions more readily if raised in these same gardens from seed.
Bloom comes as soon as it does from many perennials such as delphinium.
I like a 6-inch pot for sowing, plunging it through the summer, and bringing it to shelter through the winter freeze.
Even though these are wiry-rooted plants, when mature, they are well able to take an Eastern winter except for the Douglas iris, which is questionably hardy north of Washington, D. C.
Related: Tips on How To Hybridize Iris Flowers
Protection Methods Against Slugs
Seedlings of all these species must be protected from slugs.
A fine-meshed wire cylinder is good on a pot and provides the right shade and protection from this pest.
Screen sash instead of glass can be used in summer on a frame or flat.
One of the “meta” based baits should also be used. I surface my sowings with sharp beach sand (washed) until the iris are set in their permanent places.
However, I have never seen it advised by anyone else. Of course, the well moistened peaty, the sandy mixture is beneath the sand.