Elevate Your Garden with the Grace of Japanese Irises

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Some gardeners must just be the contrary! When the wise ones told me it was impossible to grow Japanese irises in Denver, that was all it took! “Our climate is too dry, too hot in summer, too cold in winter; our soil is too alkaline; Japanese irises are just not grown here.”

So, I scouted through the catalogs and sent off four of the oldest, most inexpensive varieties. 

Japanese IrisPin

While waiting for their arrival, we built a small, cement-bottomed, rock-lined, kidney-shaped lily pool (total cost: about $10). This was flooded several times to take away the lime curse of the cement.

Adjacent flower beds were prepared by removing all the soil for about a foot or more in-depth and replacing it with peat moss and humus. 

Japanese Irises In Their New Home

When the Japanese irises arrived, their new home, in which they were eventually joined by Louisiana irises, marsh marigolds, gentians, and shooting stars, was waiting for them.

Since they were planted in the spring, they did not bloom that same summer, but by the following summer, they were flaunting regal purple and snowy white in early July. 

Please don’t ask me their names, for they all proved mislabeled! (This is not likely to happen with irises purchased from reliable sources today.)

They continued to put up their annual display in splendid anonymity so long as we remained at that location. Like Mary, Mary, I had been quite contrary, and my garden grew.

Reasons Why I Grew Japanese Irises

You may be wondering why, aside from contrariness, I was so determined to grow irises that I had been assured was a waste of time.

The first reason was that anyone so devoted as I am to the iris wants some to bloom in the outdoor garden as long and as often as possible. 

From the first Iris reticulata in February to the last reblooming bearded iris in November, it is possible to have irises in bloom for at least part of ten months of the year, even in this mile-high climate.

There is a lull after the tall bearded stop blooming and before Iris dichotoma (vesper iris) begins, which can be filled only by the Louisiana’s (Iris hexagonal) and the Japanese.

The other reason is that if the reticulates and the dwarf beards are like little fairies, the table iris is graceful teenagers. The tall-bearded may be considered the “solid citizens” (the aristocracy or the “upper-middle-class” of the iris world, as you please).

The Japanese are unquestionably the glamorous showgirls, the gaily-costumed entertainers. Some may consider them flamboyant; others may accuse them of being un-irislike, but what might be considered extravagant against a background of the tender buds of April is exciting in July.

(Note that while the Louisiana irises may bloom in their native swamps as early as March and April, in cooler climates, they arrive in late June and early July, while the Japanese appear in July in such diverse areas as the Midwest and Oregon. If you live in the deep South, they will bloom earlier for you.)

Do not hesitate to grow these flowers because of their exotic background. All of our usual bearded garden iris are of foreign origin. In contrast, the Japanese iris is more closely related to our native American species than the bearded.

Theoretically, it should be more adaptable to conditions in many parts of the country. All our native species (with two tiny exceptions, Iris cristata and Iris Verna) belong to the Apogon group: These are beardless with narrow, heavily rooted rhizomes like the Japanese irises.

There has been some question about the pedigree of these beauties from Japan.

Modern Japanese Iris

Most experts believe that the modern Japanese iris is a highly developed form of the pure species, Iris kaempferi.

A few authorities have thought that they might be hybrids of Iris kaempferi with some infusion of the closely related Iris laevigata, which is more definitely a swamp iris than kaempferol which demands flooding only before the bloom season and tolerates dry conditions later on.

Also, the blooms of modern varieties more closely resemble those of kaempferol than of laevigata, the differences probably resulting from generations of careful selection by man. To most gardeners, this may be a purely academic question.

Leading Japanese Iris Hybridizer

Still, hybridizers and collectors like to know the history of their plants, and a knowledge of ancestral species can aid all gardeners in understanding cultural needs.

Our leading American hybridizer of Japanese irises is Walter Marx of Oregon. When our grandparents planted these imported irises, the terminology needed to be clarified. 

Several years ago, when Mr. Marx began to import the finest clones available, he made every effort to obtain true stock of the varieties and to get the names straightened out.

He preferred a particular strain of exceptional superiority known as “Higos” and used them as the ancestors of a line of his development now called “Marhigos.” 

Two of the best of these ancestors were `Hisakata’ and `Karahashi.’ (I do not know of a source for these two, so please, don’t ask me. If I did, I would have them for historical interest.)

Among Mr. Marx’s more recent introductions and of special interest to connoisseurs is the truly double ‘Frosted Pyramid,’ a ruffled, pure white.

Many other Japanese irises are described as double because of the development of petaloid, and those in which the standards are flattened horizontally give a double appearance, so this iris often more closely resembles a peony than they do other members of their own family.

Newest and Rarest Japanese Irises

Others of the newest and rarest are the following:

  • ‘Frilled Enchantment,‘ a large, ruffled white, bordered in bright rose-red
  • ‘Geisha Dance,’ described as red, white, and blue
  • ‘Blue Pompon,’ almost a deep navy blue with bright gold signals and measuring a full 8″ inches across, with a pompon center
  • ‘Apple Blossom Cascade,’ which may not be liked by those preferring the flat, saucer form over the draped effect, but which has a 10″ inch spread and is a beautiful orchid-pink hue

A little older and less expensive but highly deserving of a place in the collector’s garden are the following:

  • ‘Hoyden,‘ a bit smaller than some but still reaching as much as 6″ or 7″ inches in its single, two-colored blooms
  • ‘Great White Heron,’ one of the largest and whitest of all
  • Stippled Ripples,’ with a stippled rose-red border
  • `World’s Delight,‘ the closest approach to a true rose-pink self
  • ‘Vain Victor,‘ with a splendid, dark red border
  • The deep, velvety purple’ Summer Storm’

General Type Japanese Irises

If you are more interested in the general type than in named varieties, select from the Grand Opera Series at a low price, in which you can choose color and pattern. Still, the individual clones are not separately named.

Perhaps Madame Butterfly is your favorite opera, and you would like to choose a plant from the “Butterfly” series and receive a delicately bordered or stippled one.

If you think Pinafore is more fun and like lots of good blues in your garden, this is the series for you; while those who like dash and verve and the brilliance of warm purple, which can nearly be called red, will select something from the Carmen series. 

Matron, Parsifal, Rigoletto, and Rhine old all find devotees.

Two of the best imported Higos are `Nishiki-Gi’ (`Brocade Trees’), a richly marbled white and purple, and my favorite, `Torizan,’ widely banded in rich, rosy red.

For beginners wishing to cut their teeth on older, reliable varieties before progressing to newer ones, longtime favorites, available from many sources, include:

  • `Nishiki-Yanaa’ (`Brocade Mountain’)
  • ‘Red Emperor,’ `Norma,’ Gold Bound’
  • Mrs. J. S. Hayden’ and ‘Rose Anna.’

Another economical way to start is to collect unnamed seedlings from a good hybridizer.

“Well,” you may think, “that is all fine to read about, but I have neither pool nor stream, so how can I grow them in my garden?”

Japanese Irises At The Waterside

It is not necessary to grow gorgeous Japanese irises at the waterside. While a pool is convenient because it is easy to flood the pool and iris simultaneously (and the floods of spring do the same for us now that we have moved our own beardless’ irises to a streamside),

All you need is a corner of your garden that you are willing to keep quite wet from spring into July—perhaps even a low place that has hitherto been a problem to you, although there should be some drainage.

If your soil is alkaline rather than neutral or slightly acidic, prepare the bed before your plants arrive by removing any heavy clay and filling it in with peat or your favorite form of humus.

If you still fear alkalinity from the local water, apply sulfates (I usually prefer iron sulfate for our conditions, although ammonium and aluminum sulfates may be used, but do not overdo them).

Grandmother did not have this problem, for she had her cow and horse! Such a dressing should not be needed more than once or twice a year, and if your soil is acidic, it will not be needed at all. Wherever you are, DON’T ADD LIME!

Then remember that, unlike the bearded irises, which do not object to sunbaths for their toes, all beardless irises, including the Japanese beauties, are very modest about their feet and want them well-covered with mulch at all times.

If this is taken care of, they can be planted in full sun, even in the sunshine states. If your winters are sub-zero or given to alternate freezing and thawing, it is better to plant Japanese irises in the spring so they may have all summer to get established. Otherwise, they may be planted in the fall.

With these few precautions in mind, you may be surprised to discover that these irises are far less troublesome than many hardy perennials and shrubs you see planted everywhere, and often they are more rewarding.

44659 by Lys Housley