How to Grow Hellebores

Hellebores are an easy to grow perennial. Most Hellebores are low-growing plants reaching about 3-.5m high. They flower from December through to spring, depending on the variety. Hellebores have a wide range of flower colours crimson, red, subtle pinks, various shades of yellow and white, many with attractive speckles inside the flowers. There is also a bright green variety of Hellebore, illustrated centre top, Helleborus argutifolius, the Corsican hellebore, which is one of the few tall varieties reaching  60cm.

Hellebores are a fast moving group of plants because new hybrids are being developed all the time and there are dozens of wonderful varieties on sale, with more colours, doubles petals, and some with more upright flower heads. Below are two recent additions to the Helleborus family. Developed from a breeding programme painstakingly undertaken by Rodney Davey to combine strong colour and marbled foliage. 

Most Hellebores routinely offered for sale are Helleborus hybridus ( previously known as H.orientalis,) commonly known as the Lenten rose to distinguish from Helleborus Niger, the Christmas rose which flowers earlier.

 In the garden many Hellebores will self seed and multiply into clumps as in the image top left. Most of the popular varieties of Helleborus are small plants, growing up to around half a metre, suitable for the front of a border, also good in a woodland settings and as ground cover. Many varieties have nodding flower heads which hang down.  Hellebores are usually evergreen, although also semi evergreen/deciduous in cold winters.

Crocus has a lovely selection of over 50 Hellebores on sale. (affiliate link)

 Helleborus are tough, versatile plants. Their preferred growing conditions are neutral to alkaline soil with dappled shade. That said, Hellebores will tolerate a wide range of growing conditions, excluding only very wet or dry conditions. This makes Hellebores suitable for planting almost anywhere in 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. 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).  Hellebores are reliable and flower every year once established with little or no attention. Most are very hardy, H5 which is -15 -10. 

Plant Hellebores in partial or dappled shade. Excessive shade will reduce flowering if you plant there. Hellebores look good under-planting shrubs. In this arrangement, it is best to raise the canopy of the shrubs to reduce the shade. 

Hellebores require little or no routine maintenance. If you have time, I think Hellebores do best with the old foliage removed in late winter. (see 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, the gardeners remove all the old foliage. 

The second reason to remove foliage 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, it is safe to remove them in late winter and new foliage will grow ready for the spring to carry on the photosynthesis. As a woodland plant, hellebores  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 in more exposed gardens.

Advice varies about removing leaves from Hellebores. 

There is consensus that Hellebores are prone to Leaf/Black spot characterised by unsightly brown and black patches on the leaves. There is agreement that all infected leaves should be removed, and not composted. Some growers remove leaves in November/December, some in January and some remove only the previous year's growth, others remove most of the leaves. 

I tend to remove most of the leaves in January to display the flowers and make way for the new leaf growth, which will follow the flowers. As the images below show, the foliage can be in a poor state by January with evidence of leaf spot. The second image shows the same plant after cutting back with a mulch of leaf mould. So if your Hellebores are looking sickly, be bold and take heart from these images that the plants will quickly come back, and look better.

Some varieties of Hellebores self seed.  To ensure the safe passage of the tiny seedling, it can be better to dig it up and pot on into a small container and grow for a season and then plant out. Not all will self seed, and even if they do, the resulting plant will often be different, and inferior to the parent plant. Unless you have a large area to cover and are looking for an economical way to fill it, you may wish to dead head Hellebores to preserve the integrity of your existing stock of plants.

You can also collect seed, which will be around May time. The seed is best sown immediately and leave the pots outside to get a cold spell and they may germinate later/the following year. Growing from seed can be a slow process and I find nature does it better than I do. Just leaving the Hellebores to self seed usually produces a few new plants each year.

Hellebores are widely tolerant of most conditions if you have a particular spot in mind, it is worth considering the following tips.

The Hellebores lenten rose types will grow almost anywhere. They are best in damp, well drained soil in dappled shade. If grown in sunnier conditions, the soil needs to be more moist.

If you want to grow Hellebores in dry shade, a variety to try is  Helleborus x nigercors or  H. foetidus (the stinking hellebore, possibly not so attractive)

In sun, Helleborus x sternii and Helleborus odorus, the latter is a green variety, fragrant and both are slightly tender. 

Divide Hellebores to create new plants for free. This may be better than self seeding as your new plant remains true to the parent plant.

Helleborus niger (Christmas rose) is best divided in the spring and Helleborus x hybrids, the lenten rose  and the orientalis varieties, are best divided in the late summer or autumn. However, Hellebores is a tough plants and should survive being divided at any time, unless the weather is bad over the winter and/or when they are in full bloom. This means most Hellebores can be divided in mid to late spring,  and if you are not sure what type of Hellebore you have, divide it after flowering later in the spring.

To divide, lift the clump, keeping as much root as possible, cut into largish pieces about 15cmc each (6") and replant, watering well. After replanting, Hellebores may take a little while to re-establish, which can mean a lack of flowers in the following late winter/spring, but they should do better after that. 

There are two types of Hellebore which are not suited to division.  Helleborus foetidus, known as the stinking Hellebore and it is tall, up to .5m and predominantly green,  and H. argutifolius, the Corsican Hellebore  (top centre image) which is similar to look at, mainly green flowers and similar size but with prickly leaves. If your Hellebores are tall with green flowers, it maybe  best not to divide them.

Hellebores are more or less trouble free except they can suffer from the common fungal problem of leaf spot, which as the name suggests means the leaves get marked with black or brown marks. The image below shows what Hellebore black spot looks like,  and the simple solution is to cut off infected leaves.

If the infection is severe, cut off all the leaves, the plant will survive.  The plant does not seem to suffer from having many leaves removed, and new ones replace them in the spring. Always remove any leaves which are brown or black even if it means the plant is almost denuded, it will survive and as always, with infected leaves, do not compost. 

Hellebores can also get Black death, which causes black streaking on the stems, leaves and even flowers and looks different to Leaf Spot as is distinct streaking often along the veins. Eventually, if left unchecked, it will kill the plant. The solution is to remove the leaves at the first sight of it, the same as with Leaf Spot. In common with many plants Hellebores can get Downy mildew, a fungus, covering the leaves with yellow spots and off white mould. Remove and bin affected leaves.

Remember Hellebores are a poisonous plant, (humans and pets) and ingestion of root or leaves can cause stomach upsets, and for some people they are also a skin irritant.