When to plant: Plant hellebores any time in the fall or early spring. As long as the ground isn't frozen or the weather too hot, you can plant hellebores in your garden.
Hellebore Growing Conditions
Best Soil Conditions: Hellebores grow best in moist, well-draining soil enriched with generous amounts of organic matter. Site them where it’s damp, but not wet.
Watering: Hellebores enjoy moist (but not soggy) soil. Provide supplemental irrigation in dry conditions to maintain soil moisture. A deep watering once a week should be adequate, however, testing the top few inches of soil with your finger is the only way to know for sure if the soil has the appropriate amount of moisture. The soil should feel lightly moist, but not water-logged or soggy.
How to mulch hellebores: Mulch annually in fall, and allow leaves to remain as a natural mulch and soil conditioner. You can pull back old leaves from the foliage in late winter to expose the foliage and new blooms.
Best soil pH: They also prefer a pH close to neutral, even alkaline. Add lime if your soil is extremely acidic.
Light conditions: Hellebores prefer full shade to partial shade. NOTE: Designers and gardeners often plant hellebores under deciduous trees for a wintery show, followed by helpful cover shade for the foliage in summer.
When and what to fertilize: Feed the plants in the fall with a balanced fertilizer, a layer of compost, and/or bone meal.
Foliage that emerges before flowers (or that's leftover from last season) can look winter-tatty. You can prune this old foliage off as the hellebore starts to flower, which will leave you with bare stems. Or, if you don't mind the winter imprint on the foliage, prune out the old foliage when new leaves start to come out, about two months after bloom starts. Either approach is fine for your plants. It all comes down to your aesthetic and personal preference.