(1913) Forcing Iris
Gardeners' Chronicle of America, p.578, 1913
The forcing of Iris is a profitable florist's venture, especially when timed so that the blooms come in March. Iris Germanica is the best for this purpose, particularly the four following varieties : 'Mme Chéreau', pure white with light blue edge; Trautlieb, a splendid delicate pink; Florentina albo, pure white mottled sky blue ; Atroviolacea, violet lightly veined white and blue.
The Iris on being divided after blooming are planted into beds and well watered. They are given frequent doses of liquid manure during the summer. The Iris like a damp, loamy soil, the richer the better for producing well developed plants. In late fall the plants are taken up with the balls and set close together in a house or cold frame. They should be at least three feet from the glass, to prevent the blooms from touching it later and getting injured. They grow quickly with a temperature of 50 to 54 degrees, and will be in splendid bloom within twelve to thirteen weeks, if given plenty of air, water and liquid manure. All faded or dead leaves should be removed at once, for Iris easily damp off in forcing. For shipping it is important to cut and pack them in the bud ; open Iris blooms will stand no pressure, but the buds open freely when unpacked.
Other good varieties for forcing are Iris Hispanica and I. Anglica, both of which furnish valuable cut flower material. Like the preceding, they should not be forced too early or the loss will be too great. The bulbs of both of the above Iris may be planted in August in boxes, like Tulips, and brought into forcing when well rooted. The treatment otherwise is similar to that of Iris Germanica.
Iris may be forced many years in succession. They should be divided immediately after blooming, the rhizomes being planted in a cold frame and covered with sash, and later transferred into outdoor beds as soon as the weather permits, – Moeller's Deutsche Gartner-Zeitung.
For more information on historic Irises visit the Historic Iris Preservation Society at