Hellebores are some of the earliest blooming flowers in our gardens. Searching for hellebore’s soil preferences takes us to the southern and eastern European mountains. The native soil and root morphology tells us what we need to know about growing hellebores in our gardens.
I’ll never forget the first time I saw a hellebore. It was a gray January morning at VanDusen Botanical Garden in Vancouver, British Columbia. My landscape design instructor, Nel Grond, introduced me to hellebores 20 years ago. The droopy pink hellebore flowers peeped out through their large evergreen leaves. It was love at first sight. Anything that blooms in the middle of winter has my vote.
Species and hardiness
At Plant Hardiness Zone 7, Vancouver’s climate is perfect for growing hellebores, which prefer to grow in zones 6 to 9. Not all hellebores hardiness zones are alike though. There are 15 species of hellebores, but four are more commonly found:
Lenten rose — Helleborus orientalis — USDA Zone 5-9. Partial shade to full shade. Produces pinkish white flowers.
Christmas rose — Helleborus niger — USDA Zone: 4-9. Partial shade to full shade. Has large white flowers, and occasionally with a pinkish green tinge.
Corsican hellebore — Helleborus argutifolius — USDA Zone: 6-9. Partial shade. Produces sprays of small apple-green flowers.
Stinking hellebore — Helleborus foetidus — USDA Zone: 5-9. Full sun to partial shade. Has small soft green flowers with a red edge.
Hybridization between the different kinds of hellebores has created plenty of hellebores with blooms of almost every any colour. Monrovia features eight of their favourite hellebore hybrids. Sadly, most hybrid hellebores are less cold hardy than the species hellebores.
Soil preferences for hellebores in most factsheets tend to be generic. Well-drained loamy soil. The Shangri-La of soils. Soils which hellebores naturally grew in their native habitat is most likely to be different from this “perfect” soil, and probably more feasible for the average gardener.
The hunt for the native soil, takes us to the high mountainous regions (1,300 ft. up to 7, 500 ft.) of southern and eastern Europe, the Alps and the Carpathians. Here, hellebores naturally grow in the shade of spruce, birch, oak and beech woodlands on chalky, porous stony clay soils.
What a wealth of clues!
Hellebores soil pH preference is neutral to alkaline earth, although they can grow in slightly acidic soils too.
Stony porous clay soil in a woodland habitat
Hellebores CAN thrive in clay soil if it’s well drained and high in organic matter. Sandy soils may also work as it naturally has good drainage. All you would need to do is add plenty of organic matter to perfect it. In both cases, the soil is moist, but not wet, thanks to the ground’s high organic content and good drainage.
Getting down to the roots
Examining plant’s roots provide more clues to the kind of soil it prefers. In hellebore’s case, they have long and fleshy roots. Not wet soil roots. The roots shape hints at their drought tolerance potential.
Hellebores need moisture when flowering and seeding, but can withstand some drought in the summer. H. orientalis, the Lenten rose, can withstand drier conditions than H. niger, the Christmas rose.
Hellebore’s long fleshy roots hint at their slow establishment in the garden. Tracy DiSabato-Aust’s The Well-Tended Perennial Garden reveals that “[hellebore] plants are slow to take hold, but are long-lived and don’t need to be disturbed once established — division is seldom.”
In the right soils, hellebores don’t need any extra fertilization; it gets all its nutrients from its organic-rich soil. But if you see your hellebores struggling step in.
Water hellebores during prolonged drought.
If the hellebores are not growing well, add a smidgen of fish, blood and bone to the soil in the spring (a little above 1 lb. per 100ft2).
Mulch (preferably with leaves) every year to keep the ground moist, and high in organic matter as the mulch decomposes.
Hellebores look amazing grown in mass. But if you like variety as much as I do, there’s an excellent selection of shade plants that grow with hellebore including ferns, epimediums, pulmonarias, bleeding hearts, hostas, cyclamens, trilliums, wild ginger, acorus and carex.
Why not invest in a hellebore (or two)? Their soil and growing requirements are straightforward, and the plants are relatively pest-free. The drooping flowers in the garden or floating face up in a bowl indoors, will, for a moment, make you forget winter.