The genus Helleborus consists of 15 different species of hardy, low-growing, mostly evergreen perennials that bloom in a range of colors in late winter or early spring with long-lasting flowers. With careful selection, a hellebore could be blooming in your garden from November until mid-April! These plants thrive in dappled shade, are deer-resistant, are relatively drought-tolerant once established, and have very few pest or disease issues.
Woodland conditions are ideal with deep, fertile, humus-rich soil and dappled shade or just morning sun. Hellebores are tolerant of a wide range of soil conditions, as long as plants have good drainage; not tolerant of soggy soils. Plants may flower poorly or produce smaller blooms if grown in deep shade or potentially show stress/sunburn in hot sun. Plant or transplant in spring or fall; mature plants do not like to be moved or divided. Cold-hardiness depends on species with some hardy to -20°F!
Care & Maintenance
An annual application of balanced, all-purpose fertilizer in late winter to early spring will keep plants growing well. Mulch around the plant with compost in early winter, but keep away from the crown to prevent rot. Many gardeners remove old leaves to maintain a tidy appearance when flower buds first appear.
When flower stems are 3-4 inches tall, cut off all the old leaves. This will enhance flower display and reduce the spread of disease year to year. When flower stems die back, they may be removed as well. Seedlings that appear around the base of plants may be left if not overcrowded; otherwise, pot them up or move them in spring. Some cultivars are sterile and will not form seeds.
When plants are well established or if they become congested, they may be divided. The best time to do this is late summer or early fall when active growth has slowed. Be aware that recently divided plants may take a year to reestablish and may skip a season of blooming.
Because they thrive in dappled shade, are fairly drought-tolerant, and bloom when most plants are dormant, Hellebores are a great addition to any landscape. Their compact growth habit makes them excellent container plants as well. During late spring and summer, when out of bloom, their leathery, dark green foliage combines nicely with patterned leaves of Hosta or the ruffled foliage of Heuchera. Other wonderful woodland shade garden companions include ferns, Brunnera, Bleeding Hearts, and Epimediums.
Hellebores are also deer-resistant and somewhat drought-tolerant once established. Being mostly evergreen, their large, textured, dramatic leaves provide structure and color year-round. Combine all of these desirable qualities with overall toughness and you get a stellar perennial worthy of inclusion in every garden!
Several varieties have been bred to have patterned or otherwise interesting foliage such as the ‘Frost Kiss’ series, and many cultivars in the Gold Collection such as ‘Pink Frost’ have blue-green leaves with burgundy tinted stems. Recent introductions like ‘Merlin’ and the ‘Ice N Roses’ series produce extra-large, outward-facing flowers.
Pests & Diseases
Hellebores have few problems with disease, but they are susceptible to black fungal rot. Keep an eye out for aphids as new growth emerges and treat with neem oil or insecticidal soap, or rinse off bugs with a strong blast of water. Slugs and snails are also known to attack young growth, so bait with Sluggo before new growth begins.
Bloom colors depend on the cultivar, but tend to be mainly pastel shades with occasional dark colors in reds and purples (some even nearly black). Each flower lasts for several weeks and often goes through subtle color changes as it matures. Plump seeds eventually develop in the center and often self-sow in the garden, creating a mass of plants over time. Flower forms are single, double, or semi-double and most flowers have nodding habits on short stems. However, several selections have been bred for longer stems and outward-facing blooms—the flowers have to nod somewhat to protect the pollen from becoming wet, since, at the time they bloom, they are exposed to extreme weather. If the fallen stamens sit in a pool of water in an upward-facing flower, it is likely that the flower will rot. Hellebore cultivars have names such as ‘Winter Jewels’, ‘Gold Collection’, and ‘Winter Thriller’ which allude to their elevated status as one of the few coveted flowers of winter. See the chart below for examples of different bloom times for some common Hellebore cultivars.
Other late winter/early spring flowering trees and shrubs: Edgeworthia, Daphne, Sarcococca, Magnolia, Viburnum, Camellia sasanqua (fall/winter), Witch Hazel, Winterhazel, Mahonia, Azara, Forsythia, Fothergilla
Perennials: Epimedium, Cyclamen coum, Bleeding Heart, Euphorbia, Pulmonaria, Bergenia, Hardy Primula, Heaths & Heathers, Evergreen Clematis