This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
This is grown extensively in some market gardens between rows of Apples, Pears, Plums, etc, chiefly for the large pure-white blossoms which appear naturally at Christmas time and later. The plants like a rich, cool, moist soil and semi-shaded places, and should always be planted early in spring after the flowers have faded. For forcing purposes they are very valuable. Clumps are lifted in November or earlier, just as the buds begin to appear, and are placed in shallow boxes. These are transferred to a greenhouse with gentle warmth, and when kept just moist the flowers open with great purity of colour, and are then bunched up for market, the prices realized varying from 3d. to 6d. and 9d. per bunch according to circumstances. Clumps that have been gently forced in this way are afterwards planted in the open, and are not forced again until at least two winters later. A fresh batch of plants is used instead, and they rest in due course while another batch is being forced into early bloom.
There are many kinds of Hellebores besides H. niger in which nurserymen do a trade with owners of private gardens, etc. The following may be noted: orientalis, the Lenten Rose, with rosy flowers from February to May; odorus, green and purple, fragrant; atrorubens, deep purple; punctatas, pale red, spotted; colchicus, bright purple; foetidus, greentipped purple; olympicus, purple; and many beautiful hybrid varieties known under the name of guttatus.
Fig. 207. - Helleborus niger.