Stinking hellebore

Questions about stinking hellebore

Does stinking hellebore need sun or shade?

Stinking hellebore grows in part shade (2 to 4 hours of sun, mostly in the morning) and shade (less than 2 hours of direct sun, or bright dappled light). It is one of the few that also put up with deep shade.

It wants ordinary well-drained soil, of average fertility, and little watering once settled. Once settled in, it stands drought.

What zones does stinking hellebore grow in?

USDA zones 5 to 9. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).

Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.

When does stinking hellebore flower in my zone?

In zone 5 it flowers late February to mid April. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.

Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.

How far apart should stinking hellebore be planted?

18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.

It grows 24 in (60 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many stinking hellebore plants do I need?

At 18 in apart, set out in staggered rows:

• 5 to fill 10 square feet (about 1 m²)
• 7 for a single row 10 ft (3 m) long
• 17 to fill a 4 × 8 ft bed on its own

In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.

In the bed above, the planner used two in two groups.

Is stinking hellebore poisonous to dogs and cats?

Yes: moderate toxicity to people, dogs, cats and horses. All parts are poisonous if eaten. The sap can irritate skin and eyes.

Rated from NC State Extension. Where references disagree, the more cautious rating is used.

Do deer eat stinking hellebore?

Mostly not. NC State lists it as resistant to deer and rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.

Will stinking hellebore spread?

It seeds itself about; the risk of it taking over is moderate. Short-lived, but keeps going by self-seeding. Thin or move seedlings where they are not wanted.

What flowers after stinking hellebore?

Stinking hellebore is over by mid April. These start as it finishes and carry the same spot on, so it never goes flat:

• Red barrenwort: from late April to mid May, 12 in tall, to stand in front of it and cover its fading stems (a recorded partner).
• Columbine: from early May to mid June, 24 in tall.
• Lily of the valley: from early May to late May, 8 in tall, to stand in front of it and cover its fading stems.

What does stinking hellebore look like in winter?

Stinking hellebore keeps its dark green leaves all winter, so it is one of the plants that hold a bed together from November to March, when the perennials have gone. It is grown for winter structure and flowers in dry shade as well.