Helleborus are tough, versatile plants. Although their preferredgrowing conditions are neutral to alkaline soil with dappled shade, Hellebores will tolerate a wide range of growing conditions, excluding only very wet or dry conditions. This means Hellebores are plants you can place in most parts of the garden. Hellebores are quite vigorous and quickly multiple to make larger clumps.
Hellebores flower from December through to mid-spring, although the flowers may stay on the plants longer as they slowly fade, but still look attractive. Many Hellebores are self seeders, (although not all the modern hybrids which do not always produce seed.) If you want to restrict the spread of Hellebores, remove the spent flower heads. When they self seed, the new seedlings will form a clump near the parent plant which will flower after two or three years, a process which over time creates clumps of Hellebores( image above left) which look good in a natural or woodland setting. Hellebores are reliable and flower every year once established with little or no attention. Most are very hardy, H5 which is -15 -10.
Hellebores require little or no maintenance, but they do better if you have time,if the old foliage is removed in late winter. ( see How to do this images below.) Removal of most or all of the foliage displays the flowers at their best, leaving just the new young foliage coming through. Cut back carefully, because at ground level the flowers buds are forming along with new foliage. In some professional gardens such as the RHS, all the old foliage is removed to show off the flowers.
The second reason is that Hellebores are prone to black spot, and by Dec/Jan the leaves can have evidence of black spot to a greater and lesser degree. In 2017/2018 we suffered a wet winter. As a result I cut all the leaves from the Hellebores to remove the black spot infestation.
Although the leaves are required for photosynthesis, they can be removed in the Winter and new foliage will grow ready for the spring to carry on the photosynthesis. As a woodland plant they benefit from a mulch of leaf mould, (image below right) although any well-rotted organic matter will be suitable.
Most Helleborus are fully hardy and will grow reliably year after year. Some Helleborus × hybridus are borderline, which means they may need winter protection, especially in more exposed gardens.
Hellebores are ideal for under planting deciduous shrubs.