Description and general information
Helleborus niger is a member of the Buttercup family, Ranunculaceae. This species is among the shortest of the genus. Plants produce a cluster of relatively short-stemmed (20 cm), pedate, leathery, evergreen leaves. White or pink-tinted flowers are commonly produced individually atop stems that reach 15-30 cm. The 4-8 cm diamter flowers are composed of 5 'petals'(actually modified sepals) and last for several weeks.
The species hails from forested to alpine, limestone regions (1000-6000') in the mountains of southern Germany, Switzerland (eastern Alps) to Italy, Slovenia and Croatia (northern Apennines).
This species is hardy to USDA zone 4. Plants are known to be difficult in cultivation compared to others in the genus. They prefer a partially shaded site with deep, rich, well-drained, limestone soil.
In very mild regions, H. niger can live up to its common name of Christmas Rose, by blooming in December. In colder regions, they may bloom as late as May.
The seeds of most hellebores are short-lived so fresh seeds should be sown as soon as possible after being shed by the plant. They require a stratification period for best germination. Sow fresh seeds by mid-summer and leave them in their pot outside for the winter. Seeds take 3-4 years to reach flowering size.
Helleborus niger is among the easiest of the hellebores for dividing. Dig plants after they have finished flowering. Gently shake them free of soil and pull the crown apart. This species is relatively long-lived and improve with age so it is best not to overly divide plants into too many small pieces.