Hellebores sound like a dream come true. They really do bloom when the garden looks wintry and the ground is still dotted with the last traces of snow. The flowers are big, bold and abundant, and they come in several colors--pinks, purples, dusky reds, white, pale green and even some yellows. And their color range keeps expanding as plant breeders give more attention to these up-and-coming perennials. What's more, hellebores are shade lovers, which is good news for maturing gardens. Perhaps most impressive of all, however, is that the foliage of most kinds of hellebores is attractive year-round. No wonder knowledgeable plantsmen rank hellebores among the top 10 high-performance perennials.
It's not just that flowers of hellebores come so early that makes them appealing to gardeners: They stay awhile as well. Because the buds begin to emerge during very cool weather and the whole process occurs slowly, the display can go on for months. Individual blossoms can range in size from an inch to three inches across (depending on the species) and are shaped like giant buttercups, to which they are related.
What sets hellebores above most other perennials, though, is their striking foliage, which looks good year-round in most locations. I hear that the leaves are even able to come through hailstorms in good condition. The foliage of most kinds is leathery and a beautiful deep green. Individual leaves are deeply divided and "palmate", which means they are shaped roughly like a very large hand spread wide. They might remind you of mayapple or of pachysandra.
Hellebore foliage combines well with other shade-loving perennials like wild ginger (Asarum), cyclamen or Pulmonaria, as well as with bulbs such as snowdrops or miniature daffodils. Plant these combinations under open shrubs or trees with high shade. Serious ground covers like vinca, pachysandra or ivy are too aggressive to make good companions. An established clump of hellebores will cover a patch of ground quite effectively, but the plants spread so slowly and are so expensive that they can't be rightly classed among classic ground-cover plants.
Individual hellebore plants are long-lived. They don't ever need dividing and, in fact, they recover slowly from any root disturbance. Division is a very slow way to propagate hellebores (some can't be divided), which is one reason the plants are still fairly uncommon in garden centers. Even many mail-order catalogs offer only one or two kinds. Hellebores do grow quite readily from seed, however. The easiest way to get more plants is to move the seedlings that will begin to appear around the base of established plants.
There are 20 or so hellebore species. Most come from countries on the northern rim of the Mediterranean, especially in the Balkan Peninsula and into the Caucasian Mountains. Plant collectors are busy experimenting with and hybridizing these species. For gardeners, though, the four kinds described in detail here are the most widely adaptable and easiest to grow.
All hellebores fall into two very distinct groups. Plants of one kind have a stalk that holds leaves, ending in flower buds at the top. This type can't be propagated by division. The plant gets larger by making new stalks that arise just above ground level from the first stem that formed, which becomes like a crown. All stems flower at the end of their second winter. It's best to cut them back close to the base of the plant after the seeds have matured (or earlier if you don't want seedlings). Mature plants may have six or eight stems at a given time.
The other kind, which can be divided, sends up individual leaves and flower stalks separately from rhizomes underground. Each leaf and each flower cluster has its own stem. The plants get bigger as the rhizomes branch and spread. Some gardeners remove any foliage that has become tattered or weather-worn late in winter just before the flower st emerge. New leaves emerge soon after. This group of hellebores also self-sows generously in moist humus-rich soil.
Hellebores are often classified as shade-loving plants, and they thrive with some protection from the hottest sun of the day in summer. The more dependable the water supply, the more sun they can take. In nature, they often grow among tall grasses, perennials or in hedgerows where the taller plants provide summer shade. Take this cue and plant them among tall perennials in sunny borders or with ornamental grasses. While hellebores grow in a wide range of garden soils, they do best in a neutral to slightly alkaline environment.
Helleborus argutifolius (Corsican hellebore). Best for southern California, this species tolerates more sun and drier conditions than other hellebores. Stems grow from the basal crown and get two to three feet tall, topped with large clusters of pale green nodding flowers in late winter and early spring. Mature plants can be three feet across. The large leaves are a handsome blue-green. The plant is hardy through zone 6, but the leaves can suffer winter damage even in northern zone 8.
H. foetidus (stinking hellebore). This is one of the hardiest and most versatile of all hellebores. It gets its name because crushed leaves, stems and sometimes flowers emit a strange, catlike odor. It is widely adapted, growing in hardiness zones 5 to 9, and is an excellent choice for dry shade. The dark green leaves have four to nine narrow leaflets. Individual stalks get about two feet tall, and mature plants spread three feet across. The flowers appear in large clusters at the top of the stalks. Each one is pale green, occasionally edged with purple and about an inch across. The buds begin to appear in early winter and provide interest as they open slowly over the next three months.
H. niger (Christmas rose). Native to the mountains of Europe, this species needs some winter cold to really thrive, so it grows best in zones 3 to 8 in the U.S. It prefers light shade and moist, slightly alkaline soil. Typically, it flowers in late winter, sometimes even later than its cousin the Lenten rose. Evergreen leaves, which grow from rhizomes, often suffer winter damage. The flowers (one to three per stem) are a pure white that ages into rose.
H. orientalis (Lenten rose). These hellebores, which are almost always hybrids, are the best choice for most gardeners. They are hardy from zones 4 to 9, and their leaves take winter cold better than H. niger. The flowers come in the widest range of colors (white through pink, purple to yellow, as well as mottled bicolors), and they look good for a full two months. The Lenten rose is the easiest of all hellebores to transplant, and a single plant will spread quickly. It also self-sows quite readily.
Jack Ruttle is a former senior editor at National Gardening.
Photography by Suzanne DeJohn/National Gardening Association
Article published on June 23, 2008.