Saturday, November 24, 2012

Iris typhifolia Kitagawa
Siberian Iris have been gaining in popularity for decades. Garden Siberian Iris have been developed from two species, Iris sibirica and Iris sanguinea. A third species was known from a specimen discovered and collected in 1928.With flowers in three parts the race of garden Siberians now come from three species.

Its common name in the west is the Cattail-leaved iris, in China it is known as North Tombs Iris. Iris typhifolia is found in northeast China, Inner Mongolia and the southern border of Far East Russia. It has wide distribution along the Amur River valley.

It grows in ecological systems associated with water; wet meadows, permanent swamps, rivers, temporary streams, seasonal wet spots. These are surrounded by northern broadleaf and coniferous forests.
Iris typhifolia 'Caitlan's Smile

A delicate beauty
Iris typhifolia flourishes in continental climate extremes, winter temperatures below -20F, summer heat to 100F degrees. Rooted in glaciated soil types and watered by northern temperate rainfall cycles of seasonal spring rains followed by droughty summers.

Long inaccessible during the cold war it is now a contribution to our gardens from northern China. With the opening of trade in the early 80s seed was collected and distributed to Kew Gardens and iris experts in England. It first flowered in 1989, young plants often failed with moderate winter weather, bloom was arrested by late spring frosts. It was determined it preferred a later more northerly spring season due to its early bloom habit. Iris typhifolia blooms weeks earlier than its sister species.

In 1992 further material was distributed from plants and seeds collected by Dr. James Waddick, Powell University, Missouri and Professor Zhao Yu-tang of Northeast Normal University, China. Their collaboration resulted in the book Iris of China. Members of the American Iris Society who sponsored their expedition received seeds and propagated a wide variety of seedlings.

Leaves are narrow, upright and elegant, sometimes twisted. The stem base can be reddish, flower stems smooth and hollow, bracts mottled brown or with reddish spots. Species flowers are generally shades of violet- blue with no known color variations such as white found in its sister species. Variation is found in flower form since seed collection was done from a variety of native colonies. Bloom occurs in early spring, weeks before other Siberian iris species and cultivars.

Cultural requirements are similar to most garden Siberian iris; sunlight conditions are full sun to light shade, soil pH average to acidic and wet mesic soils. (Please review Siberian Iris culture sheet found in this blog site.) 

Propagation is by seed and division. Species plants from seed, hybrids by seed or division. Seeds which ripen from July to September will bloom in their second or third season.

Hybridizers have found that Iris typhifolia contributes early bloom, added hardiness, different foliage characteristics, repeat bloom and prominent signals. New hybrids have expanded the bloom season and added classic butterfly forms with some color variations in white and greater range in blue.

Iris typhifolia ‘Caitlin’s Smile’ is a selected species form with erect foliage and purple blue flowers. 'China Spring' is the first introduced Iris typhifolia hybrid; it’s a great harbinger of the coming flowering season. 'China White' is a typhifolia hybrid. 

Iris enthusiasts and gardeners should seek out Iris typhifolia for its novelty and as a companion plant in moist gardening conditions. Its flower form works well in natural gardens as an early spring accent with wet mesic ornamental grasses and perennials.

Seek specialty iris growers for purchase of Iris typhifolia and its hybrids. Seed can be purchased through the Species Iris Group of North America (SIGNA).

This delightful iris can add great delicate beauty to your spring garden.

China White

Sunday, November 18, 2012

Siberian Iris - my garden of the 1990s

I have grown Siberian Iris for decades, in the 90’s I really expanded my space for growing and hybridizing. In 2000 my garden collection was on tour for a Siberian and beardless species convention conducted by AIS Region 8.  The garden included guest plants from hybridizers around the country.

The 80’s and 90’s saw the maturation of flaring and flat rounded forms of Siberian flowers.  The process begun with White Swirl in 1957, flatten standards and flaring falls which fully close to a complete circle had reached fruition. The traditional butterfly forms with pendant or arched falls provide color from a distance. The modern flattened form looks best upon approach, looking down at the plant. All forms of flowers are acceptable to enthusiasts.

More tetraploid cultivars were introduced inspired by the success of Jeweled Crown (Hollingsworth ’85) which was the most popular Siberian of this time. It was soon to be superseded by another Hollingworth tetraploid Strawberry Fair.

Tetraploidy is induced by treating seed with colchicine or other mutagens; the surviving plantlets will have twice the chromosome count. Plants will have heavy substance, larger parts, robust growth and vibrant color. 

Jeweled Crown
I had bought Jeweled Crown in its year of introduction; in ‘87 it bloomed for the first time. The bud spathes are crimson and rise through the foliage as a band of color to burst into large ruffled crimson velveteen flowers. The signal is large and golden; all parts are of heavy substance. By the late ‘90s I had large clumps. The plant provides an impressive spring display, an excellent accent plant.

Sometimes Jeweled Crown blooms inside the foliage with warm spring temperatures. Another fault with this cultivar and nearly all tetraploids is the dense substance rips and tears in heavy weather. This is not the case with butterfly forms and diploids (normal 28 chromosome count) which are noted for their ability to hold themselves together in the worst spring weather. This ability is one of the many excellent traits of Siberian Iris as landscape perennials.
Harpswell Velvet

In contrast, Harpswell Velvet, another tetraploid, is dark blue with wire rim around the falls, an excellent example of form with arched falls and upright standards.

Ships Are Sailing
Ships Are Sailing is a remontant blooming Siberian Iris. Remontant bloom is a form of rebloom, rather than blooming in another season like some bearded iris, Ships Are Sailing blooms again, often weeks after finishing its first bloom season. This is a much sought after quality. Extending the bloom season is highly desirable to all perennial plant lovers. Cool soil temperatures appear to trigger this trait, induced by heavy mulch or cool weather and rains. I had a friend who had a daughter of this cultivar which had very late, late July bloom season. Unfortunately this hybrid appears to be lost.
Countess Cathleen
Ships Are Sailing won the Morgan-Wood Award in 2007, this high award is well deserved. With bi-tone blue ruffled flowers it is a heavy mid-season bloomer. It grows to three feet; it amplifies the landscape paired with Sea of Dreams and Countess Cathleen. This complementary group can act as a foundation for a spring garden event.
Sea of Dreams
 Another cultivar which can be combined in this group is Neat Trick, dark blue with white mottling throughout the standards and falls. Neat Trick is very popular, a breakthrough which unfortunately has not led to more mottled cultivars.
Neat Trick
Some connoisseurs do not appreciate multi-petaled varieties, but all types of forms are allowable. Concern surrounds the display of petals in a haphazard versus symmetrical display. Shebang hybridized by Japanese Iris growers Bauer and Coble makes a great spectacle.
Jamaican Velvet
A couple of intros in the ‘80s, Jamaican Velvet and Liberty Hills formed large clumps to be clustered in threes and fives throughout perennial beds. Liberty Hills is French Blue with triangular falls. Magenta colored Jamaican Velvet has blue accents.
Liberty Hills

Uber den Wolken is light blue, I have used this cultivar repeatedly in hybridizing, resulting in a few small flowered light blues with fabulous modern form.
Uber Den Wolken
All these cultivars are now common in the market through specialty iris growers.  I encourage gardeners to use Siberian Iris in their perennial beds. Comment to me how you use them in landscapes. I will compile my ideas into further blog postings. I also encourage readers to hybridize Siberian Iris, I plan further postings around this topic.