1925, Cornell Extension Bulletin #112


This bulletin has been prepared to meet the needs of the amateur or the skilled gardener who wishes to grow the irises best suited to his environment. Since hundreds of named varieties occur in the flower catalogs today. the person not a specialist finds himself bewildered by their number and their slight variations. These variations are readily detected by an enthusiast: hut they do not interest the layman who merely wishes to know what sorts will succeed in his locality and give a mass of color, height. or an emphatic note in his border. Other persons may have a dozen or more common sorts of iris of which the names have been lost. The technical descriptions, the key and the color classification should greatly assist such gardeners in roughly grouping their varieties, and, usually, in determining the names. Finally, it is the purpose of the writer to interest all gardeners in the wider use of irises by suggesting suitable cultural methods.



Austin W. W. Sand

One seldom finds so wide and so interesting- a range of color as that embraced by the bearded irises. Delicacy in tint and intensity of hue, together with the intermediate gradations of color. combine with the form. the carriage, the shape, and the size of their segments to produce subtle beauty or striking contrasts. And as if this were not enough, the translucence or opalescence found in some varieties taxes the enthusiast's vocabulary to describe the emotions awakened thereby. ln surface texture, the segments grade from a smooth, glistening, silky sheen to the richest depths of velvet; some varieties become creped, cockled, and crumpled; and some even fade or take on dull, neutral tones. The flower may be delicate as frail little 'Celeste', chaste as 'La Neige', or outstanding as 'Lent A. Williamson'.

If the iris does not appeal to any other sense, it will surely appeal to the sense of smell. Its fragrance has the odor of grape juice in 'Caprice', of clover in 'Innocenza'. of delicate Iris in 'Fairy', of very strong iris in P. odoratissima, and of bitter almond or of lemon in others. Its faint perfume is one that cannot be rivaled by that of other blooms.

The bearded iris is one of the most attractive and satisfactory plants for season-to-season effects in any garden. In landscape planting, not only does its foliage give definite line and mass but its blooms afford a glory of color which would satisfy the most exacting artist. Scales of color can be obtained by massing the sort possessing the required hue or tone. In mass planting. it is this collective use of like kinds that the public should demand. rather than a galaxy of high-priced varieties, gathered in motley array and as different in appearance as the photographs in the family album. Color contrasts can be accomplished in the highest key or in the most subtle gradation of light and shade. A succession of iris blooms can be maintained from the first disappearance of snow to the second week of July, in central New York. Plots of dwarf bearded irises in the foreground will furnish mats of blue, purple, yellow, white, and rosy lavender, and need not grow more than six or eight inches tall. Behind these, intermediate and tall bearded irises may be graded to masses five feet in height. Being perennial. in nature the plants maintain their position and increase in perfection. The iris supplies the effect of water, for a time, at least, where ponds are impracticable. Along ponds or open forest paths, their foliage makes a gradual transition to the broader open areas. For formal treatment in landscape work, they have a dignity of foliage which ties architectural features to the lawn or to shrubbery. The fan-shaped sheathes can he selected for the special shade of green desired. The matted rhizomes will assist in holding a dry, sandy terrace; will persist in shallow, rocky outcrops; and will resist the most intense heat rays of the sun. The greatest mistake a novice in iris growing can make is to set groups or individual plants indiscriminately in open areas, regardless of any pleasing relation to their surroundings.

In garden planting, the treatment of iris becomes a personal one. The graceful stems of the taller varieties, supported by the brown rhizomes and carrying slender flowers, form an artistic element in small clumps. A very formal mass may he produced by setting the plants in regular line, with the sheathes facing in the same direction. For such garden planting, the individual has hundreds of named sorts to choose from and a never-ending possibility of combinations. His interest may be color, form, number of varieties, new seedlings, or any other phase of the subject. The iris fills a very important gap between the shrubbery and the lawn, in property plantings. In formal or naturalistic treatments, the lines of walls, banks, cement stairs, and rockeries are emphasized or softened by the graceful foliage of these plants. A line of blackberry bushes, with its glossy leaves and flowers, forms an excellent background for the iris garden, helping to frame the planting and to exclude any undesirable features beyond. Companion crops are very interesting when each is given sufficient space for development. One very successful combination is that of tulips and irises. A narrow border of Iris Pumila, planted along the edge of an early tulip bed, gives color there before the tulips bloom. An iris planting can be made effective in color over a much longer period by inserting early and late tulips in groups wherever space permits. Their foliage also blends well with the iris sheathes. Salmon oriental poppies are effective with Dalmatica. The better perennial garden books offer numberless combinations in which irises are essential. One has only to study the spring landscape and the iris to evolve hundreds of interesting and intensely pleasing associations.

For ease of culture and hardiness, bearded irises surpass most perennials. Many of these plants will live thru the winter, in clumps on the surface of the ground. Their chief dislike, to weeds and to quack grass, is commendable, since nothing looks worse than a neglected, weedy patch of iris with broken foliage and puny flowers.


Bearded irises are native to central and southern Europe. his pumila, I. germanica, I. pallida, and I. variegata, in their wild forms, extended from the Alps, thru Italy, Hungary, and the Balkans, to Palestine and Mesopotamia. The forms I. trojana, I. Ricardi, I. cypriana, and I. mesopotamica belong to Asia Minor. According to Wister,' "Albicans was carried all over sonthern Europe as far west as Spain by the Mohammedans, who planted them on the graves of their soldiers. It is not known when they began to do this, but it is known that they were driven out of Spain before 750 A. D.''

Clovis T, the founder of the Frankish monarchy, found Iris pseudacorus growing in abundance along the Vienna. on the eve of his triumph over the Visigoths. He attributed his victory to this token, and ordered the flower made up in gold and velvet for the embellishment of his arms. The "Lily of France" at the beginning of the sixth century was the iris which later, under Louis I, was known by the term ''Fleur de Louis," and which was definitely fixed, by Charles V. as the French King's coat of arms,- three golden fteurs-cle-lis on a blue field.

Whether the initial popularity of the bearded iris is due to its being indigenous to western and southern Europe or an escaped exotic of the Mohammedan, matters but little. In France it bloomed so well, that it was loved for its own beauty, rather than for its mystic past in legend or physic. Space cannot here be devoted to the voluminous and interesting phases of iris lore.

Describing the commercial value of the iris, Helen E. Ricketts says:
  • "As a perfume, Iris oil was mentioned in the third century [sic], among the costly spices of the Egyptian King, Ptolemaeus Philadelphus (Ptolemy II ). As a medicinal plant it found favor with the ancient Greeks. Theophrastus, the favorite pupil of Aristotle, stated that the plants growing in Illyria and about the Adriatic throve much better than elsewhere, . . . . being less aromatic in the colder regions. He also knew that the odor of the rhizome developed after drying and lasted for about six years.

Page 10 missing.

members, aims to straighten out the nomenclature, to bring the flower into wider appreciation by the public, to encourage breeding of new and finer sorts, and to maintain or support any movement looking toward a brighter future for the iris. It materially aided the successful organization of the first International Iris Conference, at Paris, in 1922.

The botanical classification of the bearded group is a problem that will require the sincere efforts and the painstaking study of both the botanist and the plant breeder for many years to come. Masses of data covering a long-period of time must be collected, and definite crosses must be made, to establish the true parentage of our horticultural varieties.


A close study of the following key, of its terms, and of the characteristics of the plants therein classified will prepare the iris student to see the more subtle differences which distinguish the bearded-iris groups. The variations within a given group are more difficult to fix, and in the hybrids are hopelessly blended. A table arranged according to the classification by W. R. Dykes helps one to visualize the bearded-iris class and to organize them in seven groups (page 17 ).

For more information on historic Irises visit the Historic Iris Preservation Society at

-- BobPries - 2015-01-08
Topic revision: r4 - 25 Jan 2015, BobPries
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