The Classic MDBs

 by  Tom Waters

The world of dwarf and median irises was revolutionized in the 1950s when Paul Cook and Geddes Douglas crossed the dwarf species Iris pumila with tall bearded irises (TBs) to create what became known as standard dwarf bearded irises (SDBs). The new SDBs were not only lovely, varied, and useful garden plants in their own right; but they were fertile parents, leading to all sorts of new avenues for hybridizers.

Hybridizers soon tried crossing the SDBs back to both of the parent types, TBs and I. pumila. Crossing SDBs with TBs produced a whole new style of intermediate bearded irises (IBs), whereas crossing SDBs with I. pumila produced a new style of miniature dwarf bearded irises (MDBs).

'Bee Wings'
photo: El Hutchison

By ancestry, these new MDBs were 1/4 TB and 3/4 I. pumila. From I. pumila, they inherit daintiness, earliness of bloom, and floriferousness. The TB ancestry lends them a greater variety of color and pattern, and a bit more width and polish in flower form. Dwarf breeders and growers were delighted with these creations; and they became quickly popular, all but replacing the earlier dwarfs from I. lutescens breeding in just a decade or so.

'Alpine Lake'
photo: Tom Waters

The first MDB from SDB x I. pumila breeding to win the Caparne-Welch award was Alta Brown's 'Bee Wings' (Brown, 1959), which won the award in 1963.  By 1990, six others from this type of cross won the award. Especially notable among them were 'Zipper' (Sindt, 1978), a deep yellow with a stunning blue-violet beard, and 'Alpine Lake' (Willott, 1980), a soft near-white with a diffuse blue spot. I refer to these as "classic" MDBs, because they set the standard for the class during this time of great progress and interest.

'Zipper'
photo: Jeanette Graham

Another popular type of MDB was produced by crossing SDBs with each other and selecting irises that were small enough to fall under the height limit of the MDB class (currently 8 inches). These had the advantage of showing all the color patterns of TBs, including plicata and tangerine pink. Although both types were popular, hybridizers breeding specifically for MDBs preferred the SDB x I. pumila cross, which produced a much greater proportion of early-blooming, MDB-sized seedlings.

After 1990, the SDB x I. pumila cross gradually fell out of fashion, with most of the new MDBs coming from SDB x SDB breeding. The reason for this is two-fold. First, the SDBs had been steadily progressing in color, pattern, and form; and the classic MDBs from SDB x I. pumila could not really keep up. Second, fewer breeders were breeding specifically for MDBs and growing I. pumila for that purpose. Most breeders were instead working with their established SDB lines, which sometimes produce MDB-sized plants "by accident," as it were. So the SDB x SDB cross would do double duty, producing both SDBs and MDBs.

'Wee Dragons'
photo: Jeanette Graham

Classic MDBs are still being produced, however. My favorite recent one is Lynda Miller's 'Wee Dragons' (Miller, 2017). The recent Caparne-Welch winner 'Kayla's Song' (D. Spoon, 2008) is of complicated ancestry, but its overall appearance makes it likely that it too is 3/4 I. pumila and belongs in this category.

Although it is clear that the MDBs from SDB x SDB breeding will continue to dominate the class with their modern form and exciting color patterns, the classics should not be completely forgotten. The advantages of early bloom and guaranteed dainty size in all gardens should not be set aside too quickly. And since this type of cross is not often made these days, we don't have a very full picture of its potential when modern SDBs are involved.

'Kayla's Song'
photo: Ginny Spoon

Although my own hybridizing interests are focused elsewhere, I make some SDB x I. pumila crosses each year and donate the seeds to the Dwarf Iris Society seed sale, in the hopes of encouraging interest in the classic MDB cross.

If you grow MDBs, keep your eye out for classic MDBs that have I. pumila or one of its cultivars as a parent. They will delight you with their early bloom and daintier looks. 

Hybridizing with Iris reichenbachii

by Tom Waters

Four years ago, I wrote a blog post here titled “The Untapped Potential of Iris reichenbachii”. At that time, I could comment on the use of I. reichenbachii in median breeding only as a promising theoretical possibility. Now, however, I have some solid results from my own hybridizing work to share.

As mentioned in the earlier post, I. reichenbachii exists in both diploid and tetraploid forms. The diploid forms can be used with diploid MTBs, while the tetraploid forms are compatible with TBs, BBs, and tetraploid MTBs. It was the tetraploid grouping that I was interested in, so my first priority was to acquire tetraploid forms of I. reichenbachii. Alas, none of the plants or seeds available commercially or through seed exchanges have been identified as either diploid or tetraploid, so I had to make this determination myself. Not being equipped to make chromosome counts, this meant making test crosses and patiently waiting for the results.

Happily, it turns out that the tetraploid forms are not uncommon. The first two reichenbachii forms I started crossing with both turned out to be tetraploid. One is a yellow form, a collection from Mt. Vikos in Greece. The second is actually a group of plants of unknown origin I raised from seed obtained from a collector in Czechia. Most of these are violet.

I. reichenbachii ex Mt. Vikos, Greece

Waters T009-02, purple tetraploid I. reichenbachii

Waters T051-01,
I. aphylla X I. reichenbachii ex Mt. Vikos

I have three fertile tetraploid seedlings now. The yellow Mt. Vikos form gave me seedlings with I. aphylla and with the tetraploid median plicata ‘Saucy’ (Craig, 1998, IB). One of the violet forms gave me a seedling with the tetraploid median ‘Night Mood’ (L. Markham, 2003, SPEC-X). All three of the seedlings fall in the SDB height range and have the slender stems of I. reichenbachii. None are any competition for the modern, ruffled, dramatically colored median hybrids being produced these days; rather, their value is in further breeding. Because these plants are so small and dainty, they can be used to add these qualities to tetraploid MTB or BB breeding programs. So the next step is to cross these seedlings with the best modern BBs and tetraploid MTBs. It would be nice to have all the color patterns, form, and substance the modern BBs have to offer, but in a line of plants that was consistently small and delicate. This project is already well underway, as I have hundreds of seeds from using these seedlings over the past two years.

Waters T059-02,
Saucy X I. reichenbachii ex Mt. Vikos

Waters T060-01,
Night Mood X T009-02

A second project using I. reichenbachii is directed toward producing dainty MDBs. Most modern MDBs are produced by accident - they are just seedlings from SDB crosses that fall below the 8-inch height limit. These MDBs can be very lovely in terms of flower form and color pattern, but they can easily grow out of class, and often lack the daintiness and early bloom that one hopes for in a true miniature dwarf.

SDBs are the result of crossing TBs with the dwarf species I. pumila. What if one used I. reichenbachii instead of TBs? The result should plants fully fertile with SDBs and modern MDBs, but much smaller. I have three seedlings so far (more on the way) from crossing the Mt. Vikos reichenbachii with the I. pumila cultivar ‘Royal Wonder’ (Coleman, 2013, MDB). One is purple, the other two are yellow. All our about 5 inches tall, with one or two terminal buds. They bloom earlier, overlapping the pumilas and the first MDBs. They are indeed fertile with SDBs and with MDBs from SDB breeding. Once again, the value of these seedlings is not in competing with the showiest modern hybrids, but in further breeding, where they can be expected to produce a line of consistently dainty and early-blooming MDBs. Again, this project is on its way forward, with many seeds from using these seedlings with modern MDBs and SDBs.

Waters S026-01,
I. reichenbachii ex Mt. Vikos X Royal Wonder

Waters S026-02,
I. reichenbachii ex Mt. Vikos X Royal Wonder

These projects using I. reichenbachii are not for the impatient; they are multi-generation endeavors. Yet, there is something uniquely satisfying in breaking new ground.

What is a Dwarf Bearded Iris?

…and why are dwarf lovers so persistent?

 Tom Waters

'Icon' (Keppel, 2008)

In the beginning, there were no class definitions. The meaning of the term “dwarf bearded iris” was taken for granted, as all the ones being grown in gardens were similar in appearance and distinct from their taller relatives.  If you were botanically inclined, you could turn to a reference like W. R. Dykes’s The Genus Iris to get a list of dwarf bearded species, and safely assume that your garden dwarfs were hybrids or forms of those species.

The 1939 AIS Checklist attempted to be somewhat more helpful by giving a height range in addition to the list of species, setting the boundary between dwarfs and intermediates (which were stated to be hybrids between dwarf and tall bearded irises) at 17 inches. This doesn’t make sense, though, if it is taken as a definition, rather than just helpful descriptive information. What if two of those dwarfs species were crossed and produced a hybrid over the limit? Or what if a dwarf and tall were crossed and produced a hybrid under the limit? Giving both a definition in terms of ancestral species and a definition in terms of height is inviting contradiction unless it is clear whether ancestry trumps height or vice versa.

Perhaps in recognition of this, the AIS adopted a new classification in 1947, based decisively on ancestry. A hybrid involving only dwarf species would always be a dwarf; a hybrid involving only tall species would always be a tall. A hybrid involving both dwarfs and talls would usually be intermediate, but might be deemed either dwarf or tall if that was the group it most resembled. Although this last provision was strangely vague, the definition at least allowed hybridizers to cross dwarfs amongst themselves and register the progeny as dwarfs, without worry about a height limit or other factors.

This classification system was introduced at the same time as Walter Welch was organizing the Dwarf Iris Society (then called the Dwarf Iris Club) and stirring up interest in dwarf hybridizing, so there may have been some impetus to clarify definitions for this reason. Although dwarfs had been widely grown in both Europe and North America for as long as tall beardeds, they had not historically received a great deal of attention. Gardeners took them for granted, and although new hybrids were introduced from time to time, there were no hybridizers who focused on them exclusively or had planned breeding programs solely to produce new dwarfs. Welch turned that around, first by organizing a program of round robins, whereby enthusiasts (many of them recruited from gardening clubs and publications, not just iris societies) could discuss dwarf irises by mail, and then by creating the Dwarf Iris Club in 1950. I believe this was the first specialist iris society devoted to a particular type of iris. With the blessing of the AIS, the Dwarf Iris Club even trained and appointed its own judges, just for judging dwarfs!

In 1951, something happened that put the class definition under unprecedented strain. Paul Cook (a friend and correspondent of Walter Welch) introduced the first three irises of the type we now know as standard dwarf bearded (SDBs), from crossing the tiny dwarf species Iris pumila with tall beardeds. As a dwarf x tall cross, a strong case could be made that these new irises were intermediates, and indeed that is how they were registered at the time. But they were no taller than many of the dwarfs being grown at the time, so this might seem a little inconsistent. Welch and the DIS focused attention on the presence of a small branch in most SDBs, asserting that a branch was disqualifying for being considered a dwarf. Oddly, the list of dwarf species that AIS had been printing and reprinting for many years included amongst the dwarfs Iris aphylla, which is copiously branched.

The 1954 classification made
the dwarf people grumpy

Recognizing that the future might hold even more examples of such “problem children” from newfangled hybridizing experiments, the AIS suddenly reversed itself in 1954, offering a classification based entirely on height, with ancestry deemed irrelevant. This makes sense in a world where parentages have become complex or uncertain. Height is something that can be established with a ruler. Now the boundary between dwarfs and intermediates was set at a rigid 15 inches, regardless of what species the plants had come from or what characteristics they had. Welch and the DIS refused to accept this definition, appalled at the thought of 15-inch branched “intermediates” masquerading as dwarfs! Welch could be an opinionated and difficult person under the best of circumstances, and now he and his supporters had a righteous cause for contention. This caused a rift between the AIS and the DIS whose repercussions are still playing out today. From 1955 until 1973, the DIS had its own awards system, issuing the Welch Award in competition with AIS’s Caparne Award, despite the fact that it tended to be the same irises winning both awards.

Other classification issues were percolating at this time as well. There were movements afoot to recognize the so-called “table irises” and “border irises” as separate from both TBs and IBs. A committee was put together to study all these issues and propose a solution. In 1958, the AIS adopted a classification that has remained in place (with minor modifications) to this day. The dwarfs were separated by height into miniature dwarfs and standard dwarfs, with the dividing line being 10 inches. The border bearded class was created for short TBs, and the miniature tall bearded class was created for the table irises. The DIS had no interest in any of these new classes, not even the SDBs, and so the Median Iris Society was formed with the mission of promoting the five new classes between MDB and TB. A peculiar quirk of this development is that standard dwarfs are considered medians, not dwarfs, in apparent contradiction with their name.

'Alpine Lake' (Willott, 1980)
a classic MDB from SDB x pumila breeding

The 1960s and 1970s were perhaps the most exciting time in the history of dwarf iris development. Although the SDBs themselves were deemed too large to be considered true dwarfs, they had an enormous impact on breeding. Dwarf enthusiasts crossed the SDBs back to I. pumila, producing many charming hybrids, earlier blooming than the SDBs and quite distinctive in appearance, with ¾ of their genes coming from the dainty I. pumila. This became the standard cross to produce MDBs. The class was rounded out by selections of pure pumila ancestry, as well as hybrids from pure SDB breeding that happened to be small enough to fit the definition of the MDB class. These “runt SDBs” did not always meet with the approval of the dwarf purists, although there are a number of fine irises in this category. Indeed, in recent decades these MDBs from pure SDB breeding have come to quite dominate the class, in terms of sheer numbers as well as awards.

'Little Drummer Boy' (Willott, 1997),
an MDB from pure pumila breeding

In light of this history, one can understand why the DIS has remained rather protective of the little irises under its charge, and reluctant to muddle the boundary between the dwarf MDBs and the median SDBs; the dividing line between the classes was reduced to 8 inches in 1976, in part to protect the MDB class from SDB interlopers. It also explains the misgivings of many DIS members about merging with MIS, which has been suggested on a number of occasions. Any of the median classes might seem to have more cause to have its own society, given that they all have more new irises introduced each year than does the MDB class. Yet our history has set us apart, and perhaps it is the very fragility of the class in the face of the much larger (in numbers as well as stature!) median classes that inspires a certain connoisseur’s devotion amongst us.

'Pearly Whites' (Black, 2014),
an MDB from pure SDB breeding

In 2018, the DIS seemed on the brink of demise, with the president and vice president resigning, and the officers voting to merge with MIS. Rather miraculously, this was reversed in 2019, with a grass-roots rallying of the troops under the enthusiastic leadership of Charlie Carver, historic iris conservation advocate and devotee of MDBs. We now once again have a functioning society with a full slate of officers and a content-rich newsletter in final preparation for publication early this year. If you love dwarf irises and would like to be part of this renaissance, the DIS would love to hear from you!

2019 Caparne-Welch Medal

The American Iris Society

Announces

The Caparne-Welch Medal 2019

‘Beetlejuice’

'Beetlejuice'--image by Paul Black

'Beetlejuice' (Paul Black, R. 2013) Seedling #Q80F. MDB, 7.5 (19 cm). Early to midseason bloom and rebloom. Standards pale buff-pink, mid red-violet plicata stitched edge, random dotting over center, dark purple-black midrib; style arms red-grape crest and midrib, light rose edge; falls buff-cream, widely spaced purple-black eye lash lines along beards extending 3/4 way down falls, grape sanding on outer edge of haft; beards red-orange in throat, mid-orange in middle, white ends, hairs based white; slight sweet fragrance. 'Chart' X 'Kaching'. Mid-America 2013. Honorable Mention 2015, Award Of Merit 2017.

This medal is restricted to miniature dwarf bearded (MDB) irises. It is named in honor of William John Caparne (1855-1940) and Walter Welch (1887-1980). Caparne worked extensively breeding various dwarf iris species and was the first iris hybridizer to concentrate on smaller irises. Most of the dwarf iris cultivars grown in gardens in the first quarter of the 20th century were products of Caparne's hybridizing efforts. Walter Welch was the founder of the Dwarf Iris Society. After moving to Middlebury, Indiana, he met Paul Cook and began hybridizing irises. He shared Cook's enthusiasm for dwarf irises, and set out to develop new forms for the garden.

The World of Irises blog will be posting once a day all of the medal winners. The entire list of winners can be found at the AIS website, the AIS Encyclopedia and later in the AIS Bulletin, IRISES

Iris lutescens: The Dwarfs that Time Forgot

by Tom Waters

Dwarf bearded irises may be found growing wild throughout much of southwestern Europe, from Spain and Portugal, through southern France, and into northern and central Italy. Through the centuries, different botanists have encountered them in different localities and assigned different names to them: Iris chamaeiris, I. italica, I. olbiensis, I. lutescens, I. virescens, I. subbiflora, I. bicapitata.

Iris lutescens, raised from seed

By the twentieth century, it was clear that most, if not all, of these were really irises of the same species. Gardeners were most familiar with those from southern France, going by the name of I. chamaeiris, so began referring to the whole species as the “chamaeiris complex”. But the rules of botanical nomenclature require that synonyms be resolved by using the earliest published name for the species. In this case, that honor goes to I. lutescens, the name used by Lamarck in 1789. This is now the correct name for all these irises, with the exception of two irises at the extremities of the species’ range,  I. subbiflora in Portugal and I. bicapitata in the Gargano peninsula of eastern Italy, which are regarded by many (though not all) botanists as distinct species in their own right. Even if these are not regarded as belonging to I. lutescens, they are indisputably very close relatives.

I. lutescens is a delightfully varied species. The flowers are most often yellow, cream, or violet, but there are near-white forms, purples, blends, and bitones. In height, they range from about 6 to 12 inches (15 to 30 cm). The stem is unbranched, with one or two terminal flowers.

Iris lutescens 'Bride' (Caparne, 1901)

Until the second half of the twentieth century, I. lutescens  and a handful of its accidental hybrids with other species were the only dwarf bearded irises known to gardeners in western Europe and North America. Named cultivars were produced by the firm of Goos and Koenemann in Germany, by W. J. Caparne in England, and later by Hans and Jacob Sass, among others, in the US. At this time, the modern dwarf and median classes did not exist, so there was no distinction between miniature dwarfs and standard dwarfs; they were all simply “dwarf bearded”, and spanned the whole natural height range of the species, which straddles both of the modern categories.

Iris lutescens 'Path of Gold' (Hodson, 1941)

Although many people grew a few dwarfs, appreciating their charm and early bloom, almost all the attention of iris enthusiasts in the first half of the twentieth century was focused on the tall bearded. The dwarfs were rather taken for granted, by both gardeners and hybridizers. That began to change with the formation of the Dwarf Iris Society under the leadership of Walter Welch in the 1940s. Welch and his friends were determined to learn all they could to advance dwarf hybridizing, and their interest went beyond the I. lutescens cultivars to investigate other dwarf species, such as I. pumila from eastern Europe.

I. pumila is a diminutive species, about half the height of I. lutescens, single-flowered and almost stemless. Robert Schreiner had imported some seeds in the 1930s, and the species gradually became available to the new dwarf hybridizing enthusiasts. The turning point came in 1951, when Paul Cook in Indiana, who had exchanged his pumila pollen for TB pollen from his friend Geddes Douglas in Tennessee, introduced the first pumila/TB hybrids: ‘Baria’, ‘Green Spot’, and ‘Fairy Flax’. Although technically “intermediates” (as the word was used then, it meant a hybrid between dwarf and tall bearded irises), these new irises were no larger than many I. lutescens dwarfs, even though they often had a branch and a total of three buds! This launched a vigorous debate about classification, which led ultimately to the formation of the Median Iris Society and the four median classes we have today. The SDB class was created to accommodate the new pumila/TB hybrids and the taller I. lutescens cultivars, with the MDB class left for the “true dwarfs”, with a maximum height limit of 10 inches, later adjusted to 8 inches.

From the 1960s on, the SDBs from pumila/TB breeding totally dominated the world of dwarf irises. These SDBs carry an extraordinary genetic legacy (dramatic spot patterns from I. pumila, pinks and plicatas from TBs, not to mention more modern form). There was no interest any more in producing more of the overly familiar yellow or violet I. lutescens cultivars. Even the MDB class was taken over by the new SDBs. Most MDBs from the 1960s onward were produced by crossing the new SDBs back to I. pumila, or (especially in recent decades), just selecting irises from SDB breeding that happen to be under the height limit.

I. lutescens, once the very archetype of the dwarf bearded irises in gardens, is now a curiosity known only to species enthusiasts.

Is there any hope for a lutescens renaissance? At first blush, it would seem unlikely. The modern SDBs have been so developed by decades of dedicated hybridizing that they would seem to have nothing to gain (and much to lose, in terms of present-day expectations of the class) by the injection of I. lutescens into hybridizing lines.

If I. lutescens is to be heard from again in dwarf hybridizing, the opportunity may be in the MDB class. Some MDB enthusiasts have been grumbling of late that the class has been taken over by short SDBs, and is losing something of its distinctive charm. There may be some niche here for MDBs with more of a “wildflower” look, breaking away from the stiffness, width, and ruffling that comes from pure SDB breeding. Just as the MTB class has given a home to the simpler, more modest look of the diploids, perhaps there is an opening for more “retro” MDBs. I. lutescens is fully fertile with SDBs and their MDB progeny, and might add a breath of fresh air to a class that is starting to feel overworked.

Everything old is new again?

Iris lutescens campbelli

The World of Irises is the official blog of The American Iris Society. Now in its 99^th year, The American Iris Society exists to promote all types of irises. If you wish to comment on a post, you can do so at the end of the page and the author or the editors will reply. If you wish to learn more about The American Iris Society, follow the link.

The Heralds of Spring

By Virginia Spoon

After a long cold winter, nothing invigorates my spirit like going out to the garden and seeing the spring bloom of the irises. The tiny miniature dwarfs are the earliest of the bearded irises to bloom.  I love the early bulbous irises that bloom even earlier such as danfordiae and reticulata, however, the tiny bearded dwarfs are my favorites.

 Miniature dwarf irises blooming in early April. Photo--Ginny Spoon

We have a large collection of miniature dwarfs and it is sometimes hard to find a place to put them so they won't get over shadowed by the larger irises. We put one large planting on a bank and when they are blooming  in March and April they cover it with a carpet of color. 

           Miniature dwarf iris planting at Winterberry.  Photo--Ginny Spoon

Shorter than the standard dwarf bearded irises (8-16 inches), the miniatures top out at 8" tall. They are tiny and to be enjoyed to the fullest, they should be planted either in a rock garden setting or a raised area. They bloom early too, so you may want to plant them close to your house so you won't miss any of the bloom.

                     Miniature dwarf iris 'African Wine'.  Photo--Ginny Spoon

"Pixie Flirt' is a vigorous grower and it can grow into a marvelous clump in just a few years.

                                             'Pixie Flirt'  Photo--Ginny Spoon

Winter Aconite,  Snowdrops, small narcissus such as 'Tete- a- Tete' make good companion plants for the miniature dwarfs.

                                      Winter Aconite  Photo--Ginny Spoon

The bulbous iris reticulata is a good companion plant, and they bloom even earlier than the dwarf irises, sometimes even in the snow. 

                                                   Iris reticulata  Photo--Ginny Spoon

 ' Atroviolacea'   Photo-- Ginny Spoon

The miniature dwarf 'Atroviolacea' is usually the first bearded iris to bloom for us, sometimes even in the March snow.

                        

                            Miniature daffodils 'Tete-a-Tete'  Photo -- Ginny Spoon

        'Early Sunshine' usually follows second behind the bloom of 'Atroviolacea'. 

                                          'Early Sunshine'  Photo--Ginny Spoon

                                               'Kayla's Song' Photo--Carol Coleman

We were excited that our 'Kayla's Song' received the Caparne Welch Medal in 2018.

We are members of the Dwarf Iris Society and if you would like to join us contact our membership chair:  Rose Kinnard (RKinnard@minesmo.org

The 2018 Caparne-Welch Medal

The American Iris Society

Announces

The Caparne-Welch Medal 2018

‘KAYLA'S SONG’

'Kayla's Song'--image by Virginia Spoon

'Kayla's Song' (Donald Spoon, R. 2008). Standards lavender blue (RHS 92B); style arms same edged tan, darker at midrib; falls lavender blue, plum violet (77A) spot, darker (79B) veins; beards light lavender-blue tipped yellow orange (23A) deep in throat; slightly ruffled; slight spicy fragrance. 'Crown Of Snow' X 'My Kayla'. Winterberry 2009. Award of Merit 2015.

This medal is restricted to miniature dwarf bearded (MDB) irises. It is named in honor of William John Caparne (1855-1940) and Walter Welch (1887-1980). Caparne worked extensively breeding various dwarf iris species and was the first iris hybridizer to concentrate on smaller irises. Most of the dwarf iris cultivars grown in gardens in the first quarter of the 20th century were products of Caparne's hybridizing efforts. Walter Welch was the founder of the Dwarf Iris Society. After moving to Middlebury, Indiana, he met Paul Cook and began hybridizing irises. He shared Cook's enthusiasm for dwarf irises, and set out to develop new forms for the garden.

The World of Irises blog will be posting once a day the other medal winners. The entire list of winners can be found at http://irises.org/About_Irises/Awards_Surveys/AIS_Awards.html, the AIS Encyclopedia and later in the AIS Bulletin, IRISES. Pictures can be found at http://wiki.irises.org/Main/InfoAwards2018.

Dwarfs for Every Garden

by Tom Waters

The dwarf bearded irises (those classified as miniature dwarf bearded, or MDB) are a charming addition to any garden. With blooms held eight inches (20 cm) or less from the ground, they are the daintiest of all the bearded irises. They are also the earliest to bloom. In my garden, the first ones open a full two months before tall bearded season.

Almost all MDBs grown today fall into one of three categories. All three groups owe their existence to the eastern European species Iris pumila, which came to be used by American hybridizers in the 1940s.

'Liitle Drummer Boy'

The first category is Iris pumila itself. This tiny species is seldom more than 4 or 5 inches (10-12 cm) in height, with just one bloom per stem. (Actually, the stem is often almost nonexistent, most of the height being in the perianth tube formed by the flower parts themselves.) It comes in a range of colors from white and yellow to blue, violet, and purple, usually with a darker colored spot on the falls. There are a number of cultivars produced by hybridizers or selected from wild forms for their garden value. Some of my favorites are 'Little Drummer Boy' (Willott, 1997), 'Hobbit' (Miller, 2004), and 'Royal Wonder' (Coleman, 2013).

'Hobbit'

'Royal Wonder'

The next two categories came about as a consequence of the creation of the first standard dwarf bearded (SDB) irises in the 1950s. As I discussed in an earlier blog post, the SDBs were the result of crossing Iris pumila with tall bearded irises (TBs). The SDBs averaged about 12 inches (30 cm) in height and would typically have 2 or 3 buds. They are regarded as medians, not as true dwarfs, because of their larger size and occasional branch, something not seen in traditional dwarf irises.

'Alpine Lake'

Shortly after the SDBs appeared, hybridizers crossed them back to Iris pumila to produce irises of truly dwarf stature, but with a little something extra from their TB ancestry: plicata pattern, for example, or wider petals and more flaring form. These were the most common type of MDB in the 1960s, '70s, and '80s. 'Knick-Knack' (Greenlee, 1961), 'Zipper' (Sindt, 1979), and 'Alpine Lake' (Willott, 1981) are good examples of this type.

The third category came about from SDB breeding in an even more direct way. Sometimes crossing two SDBs produces an iris smaller than average. These small ones, if they are 8 inches or less in height, belong in the MDB class, since the definition for that class is based on height, not ancestry. Because so much work has been done to improve the SDB class over many decades, these are often the most "developed" dwarfs in terms of form and variety of color and pattern. Popular examples of this type are 'Dollop of Cream' (Black, 2006), 'Icon' (Keppel, 2008), and 'Beetlejuice' (Black, 2013).

'Dollop of Cream'

'Icon'

Generally speaking, the greater the amount of Iris pumila in a dwarf's makeup, the smaller, earlier, and more adapted to cold winters it will be. Those with less Iris pumila will have larger flowers with greater width and ruffling, a greater range of color patterns, and perform better in warm-winter areas.

There are no official designations for these categories, although hybridizers sometimes identify them by the number of chromosomes: Iris pumila has 32, the SDBs and their small MDB progeny have 40, and the SDB x pumila hybrids have 36.

How can you tell which of these categories and MDB belongs to? Alas, the only way to be sure is to look at the parentage on the Iris Encyclopedia or other resource. In most cases, this will lead you back either to SDBs or to Iris pumila, or else the parentage will be an SDB x pumila cross. If this sort of research interests you, my list of pure Iris pumila cultivars may help make sense of things.

I love dwarfs in all their variety, and happily live in a locale where all kinds grow well. Do you grow dwarfs in your own garden? Which kinds are your favorite?

Iris pumila: a Tiny Treasure

by Tom Waters

Iris pumila

In an earlier blog post, I wrote about how the tiny bearded iris species Iris pumila was imported to the US by Robert Schreiner in the 1930s and crossed with the popular tall bearded irises, giving rise to a whole new type of garden irises, the standard dwarfs (SDBs).

Today, I thought I would write about Iris pumila itself. Besides being an extraordinary find for iris hybridizers, it is a delightfully varied species that makes a wonderful garden plant. It is invariably the first bearded iris to bloom in the spring, starting several weeks before most of the hybrid dwarf cultivars.

In the wild, Iris pumila grows in a wide range across eastern Europe, from Austria in the west through Hungary, Romania, Ukraine, and into the Caucasus Mountains as far as Armenia and even Turkey. It is often found at higher elevations and dry, continental steppe climates. It is adapted to cold winters and sunny, open spaces. Conventional wisdom has it that Iris pumila does best in areas of colder climate (USDA hardiness zone 6 or colder), although I have grown it in southern New Mexico (zone 8), so it may be worth a try even in warmer areas.

Iris pumila is among the tiniest of bearded irises, with the tip of the blooms only about 10 cm from the ground. Usually, the stem is so short as to be hardly detectable; the blooms are held aloft on an elongated perianth tube, so that each bloom seems to be just sitting atop the rhizome from which it grows.

The species shows a phenomenal range of color. To judge from pictures I have seen on the internet, Ukraine seems to be the center of its diversity, with many extraordinary color combinations seldom seen in plants that have been imported to the US or western Europe.

The basic color may be blue, purple, yellow, or white, in any shade from pale to intensely saturated. There is almost always a darker "spot pattern" on the falls, which may be small or may cover virtually the entire petal. The spot may be solid color, or appear as rays or veins or an uneven wash of color.

You can find Iris pumila offered for sale by some alpine or rock garden nurseries. (A word of caution: non-specialist nurseries, like garden centers, often use "Iris pumila" to label any small bearded iris cultivar; these are not the true species.) Many seed exchanges have it, and growing from seed can be extraordinarily fun, since every seedling is different. It does take some patience, however, as irises take 2 to 3 years to bloom from seed.

There are also named cultivars of Iris pumila available from specialty iris growers. Many of these are registered as miniature dwarf bearded (MDB), since they meet the definition of the class. More recently, some have been registered as species (SPEC). One very popular Iris pumila cultivar is 'Little Drummer Boy' (Willott, 1997), which won the Caparne-Welch Medal for best MDB in 2005.

'Little Drummer Boy' (Willott, 1997)

Some newer Iris pumila cultivars include 'Steppe' (J. Burton, 2011), 'Keystone Oracle' (Jesberger, 2011), 'Wild Whispers' (Coleman, 2012), and 'Royal Wonder' (Coleman, 2013). 'Keystone Oracle' is notable for turquoise tones around the beard and spot, which varies from dark to pale depending on climate.

'Keystone Oracle' (Jesberger, 2011)

'Hobbit' (Miller, 2004)

'Royal Wonder' (Coleman, 2013)

I hope I've given you a taste of the beauty and variety of this diminutive iris species. Have you tried growing any Iris pumila in your own garden?