Onyx Odyssey Hellebores are enjoyable to grow because they are low-maintenance and disease/pest-free. Simply trim back last year's foliage in the spring. They can adapt to almost any growing conditions. Though they prefer rich, moist, organic soil, they will also grow in sandy or clay soil. They can even tolerate short periods of drought. The soil pH can range anywhere from slightly acidic to slightly alkaline.
Hellebores are shade plants that need to be protected from the hot afternoon sun. They will grow in full shade under large deciduous trees as long as they receive full sun from winter to spring before the trees get their leaves.
To increase the number of hellebores in your garden, mulch them heavily in the fall. The new seedlings will grow in this mulch come spring and can then be transplanted elsewhere in the garden. WARNING: Hellebores are poisonous. Do not consume any part of the plant!
Source : Helleborus 'Onyx Odyssey'