This section is from the book "The Gardener's Monthly And Horticulturist V18", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
The following hint from the Gardener's Chronicle may be of value to our " winter bloomers:" "One of the best hardy plants for forcing is Kalmia latifolia. Plants should be selected well filled with buds, and potted up in the ordinary way, and brought on in heat. Not only do the plants flower with great freedom, but they remain for a long time in bloom, and the cultivator can "cut-and-come-again" in a liberal manner. When associated with Rhododendrons, American Azaleas, and other plants in a warm greenhouse, the Kalmia has a very pleasing effect."
And here is another hint from the same source: "The Sweet Briar can be forced in order to have its young growths for use at this season of the year. We recently saw some plants that had been raised from seed, and forced the winter following the second year. The plants should be planted out in the open ground during summer, and lifted in October and November and potted in medium-sized pots, and placed in a warm greenhouse. During March and April an abundance of young shoots will repay the labors of the cultivator."