Helleborus are tough versatile plants, whose preferred conditions are neutral to alkaline soil with dappled shade, but will tolerate a far wider range of growing conditions excluding only very wet or very dry conditions. This means Hellebores are plants you can place in most parts of the garden. When planting Hellebores bear in mind they are quite vigorous and multiple quickly to make larger clumps; they need space to expand.
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. Hellebores are self seeders and so if you want to restrict this remove the spent flower heads. Hellebores are at their best from late winter to early spring. There are some early flowering varieties which look good in December, (image bottom right H. "Christmas Carol") and look good placed somewhere you can see them from indoors, or put in tubs to create a winter bedding scheme.
Hellebores are reliable and flower every year once established with little or no attention. They self seed freely, forming a new seedling 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 will grow without any attention, although they do better if the old foliage is removed in late winter December or January. Removal of most or all of the foliage serves several purposes. Firstly, it displays the flowers at their best, leaving just the new young foliage coming through. When you cut back in Dec/Jan you will need to do so carefully as at ground level the flowers are in bud forming along with new foliage. In some professional gardens such as the RHS all of the old foliage is removed to show off the flowers.
The second reason is that Hellebores are very prone to black spot and by Dec/Jan the leaves will be showing evidence of black spot to a greater and lesser degree. This year, 2017/2018 we suffered a very wet winter and I have cut all the leaves from the Hellebores to remove the black spot infestation.
Obviously the leaves are needed for photosynthesis, which is why they can be removed in the Winter during January or February, and new foliage will grow ready for the spring ready for photosynthesis. Routine removal of the leaves in Jan/Feb will show off the flowers nicely and reduce the development of any leaf spot to which Helleborus are prone. As a woodland plant an ideal mulch is leaf mould, (image below right) although any well rotted organic matter will be suitable.
Most but not all 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 good for under planting deciduous shrubs.