Bearded Irises:  The Rainbow of the Garden

I would have a hard time choosing my favorite of all spring blooming flowers.  Daffodils, irises, peonies, poppies, roses, tulips!  Too many gorgeous ones to choose from.  Well, fortunately I don't have to choose, but if I had to, it would probably come down to the iris. The variety of colors, shapes and bloom times is unequaled among perennials.  It is possible to have one kind of iris or another in bloom almost year 'round.  There are many different types and species of irises, and they are found all over the world.  So many, in fact, that it is hard to keep them straight.  But botanists and gardeners agree that the simplest way to categorize them is by type of underground structure from which they grow.  They grow either from rhizomatous tubers or roots, or true bulbs. The irises below are of the rhizomatous or tuberous sorts, and are further broken down into “bearded” or “beardless’ irises.  For "beardless" irises, please see the "Beardless Irises" page.  Please see the "Spring Bulbs" page for irises that grow from true bulbs.

I.  Bearded Irises

Bearded irises are distinguished by having a brush of soft hairs at the back of the falls that direct insects to find the pollen within.  There are several types of bearded irises including our familiar garden bearded (German) irises, the exotic arils, and certain species such as I. pallida, the orris iris, grown for its root used as a fixative in perfumery.

Aril Irises

A large group of bearded irises, the arils, are not as widely grown as the I germanica hybrids. These are desert species thriving in hot, dry climates.  They demand full sun and excellent drainage to prevent rot.   The arils have a touch of the exotic, and have some very unusual flower forms and colors distinguished by dark beards and dark signals on the falls.  Sometimes the standards are large and wide, even larger than the falls, and the falls are typically curled under.  There are many species in the aril group and they are further grouped into Oncocyclus and Regelia species. 

Arilbred irises are hybrid crosses between aril irises and bearded (German) irises.  They constitute a very exciting and beautiful selection of irises for your garden if you can provide the right conditions.  This is a very interesting and rewarding group of irises to grow, but complicated, so for further information, contact these fine organizations devoted to their culture and development.   The Aril Society International, www.arilsociety.org; and the Species Iris Group of North America, www.signa.org.

Bearded (German) Iris Hybrids

Iris germanica, bearded iris hybrids, 3-10.  Everyone's idea of what an iris should be, bearded or German irises are indispensable in the spring garden.  Named for the Greek goddess of the rainbow, bearded irises come in nearly every color, from pure white to nearly black. Pure red is the one color that eludes iris hybridizers.  Growers dig the rhizomes in the summer for late summer and fall planting.  They are best grown in full sun, and benefit from division every few years when the bloom starts to decline.   Bearded irises are further divided into six classifications based on size and bloom time:  Miniature Standard Dwarf Bearded (up to 8” h.), Standard Dwarf Bearded (about 8-16” h.), Intermediate Bearded (about 16-27 ½” h.), Border Bearded (16-27 ½” h. but bloom later than the Intermediates), Miniature Tall Bearded (16-27 ½” h. w/smaller flowers), and Tall Bearded (over 27 ½” h.)   With so many choices, one can have the right iris for almost any situation.

The form of bearded irises has changed over time.  Older, historic irises often have simpler shapes with falls that hang straight down, and standards and falls with smooth or very slightly ruffled edges.  More recent irises are quite different with flaring falls and often have very ruffled standards and falls.  Compare ‘Alcazar’ with ‘Mystic Art,’ for instance.

Bearded iris Species

Iris albicans, cemetery iris, Zones 4-9.  Pure white with yellow beards, I albicans is a natural hybrid of I germanica.  It was commonly used on gravesites in the Middle East, hence the common name, and the tradition was continued when it was brought to the U.S. in the 19^th c.  It is early blooming and very robust.

Iris x germanica var. florentina, orris iris, Zones 4-10.  The root of this iris is aromatic with a scent of violets. The dried root has long been used as a fixative in perfumes and potpourris to make the scent last longer.  Interestingly, it is also an ingredient in gin.  Besides that, it makes a lovely addition to the perennial border, blooming in April-May.  The fragrant flowers are white with the palest lavender tint to them, the falls are long and drooping with yellow beards, and rise on stalks to about 24-30." 

Iris pallida var. dalmatica, Dalmatian or sweet iris, Zones 4-9.  This iris is also grown and harvested for its roots to use as a fixative for perfumes and potpourris.  A native of Italy, I pallida has flowers of a rich lavender-blue with a fragrance redolent of grapes.  Grow I. pallida var. dalmatica in your garden for color, scent and a sense of history.

Iris pallida ‘Aurea-Variegata,’ is a variegated version that has foliage striped with gold or cream or white.  The flowers are lighter in color than the Dalmatian iris, but they both have the same intriguing grape-like scent.  Marvelous for adding foliage contrast to the garden.

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Beardless Irises

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