(1925) The Development and Culture Of The Iris by Wister
Journal of the New York Botanical Garden
THE DEVELOPMENT AND CULTURE OF THE IRIS*
* Synopsis of an illustrated lecture given in the Museum Building of The New York Botanical Garden by the President of the American Iris Society on Saturday afternoon, May 23, 1925.
The Iris well deserves its present popularity on account of its hardiness and adaptability to various garden conditions, as there is no section in which it cannot be successfully grown in America, and it succeeds also in Europe, Asia, Africa, and Australia. In America Iris may be divided into two chief divisions, the bearded flag Iris of gardens (wrongly called German Iris) which need dry soil and sunny situations, and the beardless or grassy leaved Iris, which flourish in moist and semi-aquatic situations. This latter class contains some of our native American species, as well as the famous Japanese Iris.
The bearded flag Irises have been the most popular in America for the past one hundred years. They are developed from the species native in Europe and Asia Minor, and have been greatly improved by gardeners during the last century in Europe, and during the last decade in America. Many hundreds of varieties were introduced into commerce before 1880, and these were nearly all the result of cross fertilizing by bees. Since 1880, however, many of our finest varieties are the result of careful hand-crossing by plant breeders. Among the most successful of these breeders have been Sir Michael Foster, of England, who died in 1907, and who has been followed there by Mr. A. J. Bliss; the Vilmorins and Ferdinand Denis, of France; Goos & Koenemann, of Germany, and Mr. B. H. Farr, Miss Grace Sturtevant and Mr. W. E. Fryer, and many others in America.
These bearded Irises may be planted any time between April and December in the northern states ; they should be given dry and sunny situations, and good soil enriched with lime and bone meal instead of animal manures, which are sometimes liable to cause Iris rot, a disease prevalent in some varieties in wet seasons, but which should not assume serious proportions in well-kept gardens. The only other enemy to be considered is the Iris borer, which is also best controlled by sanitary garden measures.
Plants should be divided at least every three years and while this can be done at any time, immediately after flowering is probably the best. By the selection of varieties the various Irises may be had in bloom from April to June, beginning with the Dwarf Bearded Iris such as pumila, chamaeiris and hybrids such as Socrates, Citrea, and Schneekuppe. These can in turn be followed by the Intermediate hybrids, such as Fritjof, Ingeborg, and Royal, which should carry the season of bloom down to the end of May in the latitude of New York. With them come the popular Blue Flag of old-fashioned gardens, Iris germanica, and with it the white Florentina and the purple Kochii. Then comes the group of late bearded hybrids, of which we have many fine varieties, but of which I will mention here only the following dozen: Pallida Dalmatica, Flavescens, Mme Chéreau, Iris King, Rhein Nixe, Arnols, Her Majesty, Fairy, Quaker Lady, Isoline, Aurea, and Mrs. H. Darwin. This dozen gives a wide color range, but many other varieties, equally good or better, could be chosen.
Following these Bearded Iris come the Beardless or grassy leaved varieties, among which the Siberica group, such as Orientalis, Snow Queen, and Grandis make splendid garden plants, for moist situations, as do also the Spuria group, including Monspur and Ochroleuca, and for aquatic situations the native versicolor and its near relative Pseudacorus, the yellow Fleur-de-Lis of France. These bring the Iris season along near the end of June, when the Japanese Iris (varieties of Iris Kaempferi) begin to bloom and last for several weeks. These range in color from white through to pink and blue and deep purple, in both three-petal and six-peta! forms. At present, unfortunately, through the carelessness of Japanese nurserymen, and the difficulty of reading their labels, these Irises are much mixed up in commerce, so that it is even impossible to suggest a good list of varieties.
Irises have been grown here more than a century, but the tremendous increase in the interest taken in them has led to a separate society, devoted entirely to Iris. This Society has undertaken the great task of straightening out the confusion in the nomenclature (a task similar to that undertaken by the American Peony Society fifteen years ago). It also issues bulletins and gives flower shows in different sections of the country to encourage flower growing, and it is our hope that it will prove of great benefit to all gardeners.
John C. Wister.
For more information on historic Irises visit the Historic Iris Preservation Society at