How to Grow Hellebore

Hellebore (Helleborus orientalis)
Vicki Gardner / Getty Images

The common name "hellebore" is assigned to several species of plants in the Helleborus genus of the Ranunculaceae family, which also includes monkshood, delphinium, and anemone. Hellebores used to be the domain of specialty plant collectors, but recent hybridizing has introduced several varieties that are easy to grow and readily available. The three most familiar species are H. orientalis (often called Lenten rose), H.niger (commonly known as Christmas rose or black rose), and Helleborus foetidus (commonly known as stinking hellebore). Varieties labeled as Helleborus x hybridus are generally hybrids that have H. orientalis as the principal parent.

Hellebore foliage is evergreen and forms a low clump with leaves that are lobed and palm-like. The flowers resemble roses in shape. Flower stems shoot up above the foliage but nod under the weight of the flowers, which tend to bloom face down. The plant is long blooming, with flowers that are mostly in creamy shades of white, tinged with green or pink, tending to change or deepen as they age. With hybridizing, more colors are becoming available.

Hellebore plants are among the earliest perennial flowers to bloom, welcoming spring with their rose-like blossoms. In warm locales, Helleborus orientalis can bloom outdoors at Christmastime. In colder zones, hellebores will break through the frozen ground early in the spring. Their foliage remains attractive into the summer, so they are suitable for splashy, mass plantings. They also complement foundation plantings and are ideal for woodland gardens.

Hellebores can be planted in the spring or fall. Some species are slow to develop and may require two seasons before they bloom.

Botanical Name Helleborus spp.
Common Name Hellebore, Lenten rose, Christmas rose
Plant Type Herbaceous perennial
Mature Size 1–2 feet tall, similar spread
Sun Exposure Part shade to full shade
Soil Type Rich, moist soil
Soil pH 7.0 to 8.0 (neutral to slightly alkaline)
Bloom Time Spring
Flower Color White, pink, purple, yellow
Hardiness Zones 3–9 (USDA); varies by species
Native Area Caucasus, Turkey
Toxicity Mildly toxic

Hellebore Care

Hellebores are usually planted from potted nursery specimens, even when purchased from online retailers. Hellebore seeds are available, but they are sold in seed packets that include a mix of colors. If you want a particular variety, you will need to purchase potted nursery starts because they have either been selected or hybridized for specific colors.

Bloom time depends on both the species and your climate. The Christmas rose (Helleborus niger) can bloom in December in zone 7 or warmer but rarely blooms until spring in colder climates. Most species can be counted on to bloom somewhere between December and April and stay in bloom for a month or longer.

Hellebores are very easy to grow in shady conditions where most plants struggle, provided they have some shelter from harsh winter winds. The only real maintenance the plants require is a little clean up of their fading leaves. If foliage is winter-worn, it can be cut back to basal growth in the spring, before flowering.

Light

Hellebores prefer partial to full shade. They can handle spring sun, but plant them in a spot that will become shadier as trees and other plants flush out.

Soil

Hellebores grow best in soil that is rich with organic matter and well-draining. If your soil is acidic, consider adding lime, as hellebores prefer neutral or even alkaline conditions.

Water

Although they like some moisture, hellebores should not be allowed sit in wet soil for prolonged periods of time or they will rot. Once established, they can handle drier soil.

Temperature and Humidity

Hardiness will vary with species, but you can find a hellebore suitable for USDA zones 3 to 9—most are hardy as far north as zone 4 or 5. In colder climates, protect hellebores from harsh winter winds. Hellebores tolerate a wide range of humidity.

Fertilizer

Add an organic-rich fertilizer—compost or well-decayed manure—into the soil when planting, then continue to fertilize in spring and early fall. Applications of chemical fertilizer are rarely needed if the soil is rich enough.

Is Hellebore Toxic?

Hellebore plants contain a toxin called protoanemonin. The plants are seriously poisonous only if large quantities are eaten. Consumption at this level is rare, as the plant is quite bitter to the taste and the major reason why these plants aren't touched by deer.

Symptoms of Poisoning

Ingesting the plant can cause burning of the mouth and throat, excessive salivation, vomiting, abdominal cramping, diarrhea, nervous symptoms, and depression. Contact with the sap can cause skin irritation, so wear gloves when handling it.

Hellebore Varieties

There are many wonderful hellebore varieties, often sold in a mix of colors. More and more hybrids are being offered in single colors. Here are some favorites:

  • Helleborus x hybridus 'Anna's Red': This plant has rich red-purple blooms and leaves that are veined with pink. It is suitable for zones 4 to 9.
  • Helleborus x hybridus 'Winter Jewels Amber Gem': Unique golden blossoms are edged with pink. Grow this plant in zones 5 to 8.
  • Helleborus x hybridus 'Phillip Ballard': This variety has dark blue, almost black flowers. It can be grown in zones 6 to 9.
  • Helleborus x hybridus 'Citron': This plant has unusual primrose yellow blooms and is suitable for zones 6 to 9.
  • Helleborus x hybridus 'Angel Glow': The cultivar has pale pink flowers that fade to green as they age. Grow it in zones 6 to 8.
  • Helleborus foetidus 'Wester Flisk': These plants have a red tinge to the stems and leaf stalks. Flowers are greenish, edged with red-purple. It is suitable for USDA zones 6 to 9.

Propagating Hellebore

Hellebores can be propagated by division. The best time to divide is in early spring before they flower. It is easiest to dig the entire plant and shake or wash off the soil so you can see where the buds are on the crown. Make sure each division has at least two buds. (Helleborus foetidus and Helleborus argutifolius do not divide well and are best started from seed.)

Most varieties will reseed, but if hybrids may produce seeds that don't "come true" to the parent plant. Seeds may produce plants that resemble one of the parent species, not the hybrid. You can move the seedlings to another location in the garden once they are large enough to handle and have developed true leaves.

Growing Hellebore From Seeds

Hellebore seeds don't remain viable very long. Always start with fresh seed. Fresh seed can be planted in containers and left outdoors throughout the summer. Keep the soil moist and you should see germination in either the fall or the following spring.

If you collect seeds from the pods on growing plants, they should be planted right away— they will germinate with minimal effort. However, if they sit too long outside of soil, they develop a hard coating and go dormant. It can take a year or more for them to complete this dormancy cycle.

Stored hellebore seeds need to be stratified before planting. They will do this naturally outdoors, but if you want to start seeds indoors, it will take some finesse.

First, soak the seeds in hot water until they start to swell. This can take a day or two. Then, sow them in a pot filled with potting mix and keep the pots at about 70 degrees Fahrenheit for six weeks. Finally, move the pots to a cooler spot, around 50 degrees. You should see germination and sprouting within another four to six weeks.

Common Pests/ Diseases

Hellebores don't get bothered by many insects, except for aphids. Affected parts can be removed, then spray the plant with horticultural oil or another pesticide.

The common diseases are usually fungal in origin: leaf spot and downy mildew, both of which can be treated with fungicides if the infection is severe.

One quite serious disease carries the ominous name "Black Death" which causes stunted plants and black streaks. It is caused by the Helleborus net necrosis virus, transmitted by aphids. If a plant is affected, your only recourse is to remove the plant entirely. Treat for aphids to prevent the spread of this disease.