Plant of the Season, Winter

Helleborus niger

Helleborus-niger-2For many years I made a poor showing of my cultivation skills with the “Christmas Rose”, Helleborus niger. This was always a disappointment as my parents seemed to succeed by growing their plants hard up against the south-facing brick wall of their house, extra warmth generated from the wall I felt. Many years later I was to botanise with friends in the Austrian foothills near to Kufstein in the first week of April. The goal was to photograph this hellebore in full flower in its native habitat (see photos). The species is widely distributed across Eastern Europe and in Slovenia one can find some unusual colour variants. My friends took the precaution (prior to my making a special journey from Scotland) to check out the location to make sure that the plants were worthy of inspection. The expedition involved driving up to a restaurant car park where there was still a light covering of snow. We then fitted our snow shoes and made a gentle climb in deep snow through mixed woodland of beech and spruce. After some 30 minutes ascent we came on some steep clearings (where the snow had thawed) that provided a carpet of Helleborus niger growing in modest clumps having just opened their blossoms to present a stunning display of near perfect snow-white coloured flowers. I was simply thrilled at the quality of plants and flower having never experienced such a sighting. Amongst the Hellebores were emerging Hepaticas in blue and white-flowered forms. On closer inspection I noted that the previous year’s foliage was still present, but on the point of decay, lying flat from the winter snow canopy. In a few locations, most notably beside a track-way I was able to carefully study the structure of the plant and its root-system. Looking at a cross-section of the soil profile to a depth of some 60cm, I noticed that the top 15cm was made up of semi-rotted leaf-mould or humus. Heading down, the soil predominated and consisted of gritty to stony loam made up of a deeply calcareous substrate ending up with pure gravels and stones at a depth of 60cm.

 

Helleborus-nigerHere lay the answer to my years of disappointment! First and foremost my soil pH was too acid and possibly ill-drained. Dappled shade would work and perhaps some supplementary protection of the developing buds, however these factors may not be essential. The alkalinity had an important bearing, but depth of free-drained soil with extra humus is a vital ingredient. My parents choice of situation by a wall had less to do with the protection and more to do with the lime filtering out of the mortar, I feel. Some liquid feeding (with tomato feed) of clumps during the growing season will certainly fortify mature plants to encourage flowering and I choose to de-leaf in the late autumn and then top-dress with finely chopped pine bark. The discipline of de-leafing all evergreen hellebores will help to prevent black spot and deter the attention of voles which love to devour the developing flowers amidst the protective canopy of foliage! My Granny who gardened in Eastbourne on chalky soil grew excellent hellebores, including the Christmas Rose and created a little tent to protect its flowers and ensure a fine harvest for Christmas Day! So there we have it.

Helleborus-niger-,-habitatOver the years I have encountered many fine cultivars of Helleborus niger, which would almost inevitably be further propagated from freshly harvested seed. The seed strains (as we used to call them) would produce similar offspring to the parent plant, but not identical. It would therefore be more accurate to give these strains the current name of Group, so we can offer a fine range of H. niger Potter’s Wheel Group. Some of the superior clones display a showy more rounded flower with a green eye. When it comes to propagation I would not recommend lifting established clumps and dividing them as they generally resent root disturbance. This species can be raised from freshly sown seed which van be saved and removed from the seed capsules and sown on a John Innes seed compost and given a generous covering of grit. Protect seed trays from mice and birds and I prick out seedlings once they have produced the second leaves and as with other members of the buttercup family, they prefer a deep clematis pot at potting up stage.

Helleborus-'Winter-Moonbeam'A number of variants can be found from specialist nurseries and botanical sources including Helleborus niger subsp. macranthus which is distributed in Eastern Europe and Italy. I am very familiar with this variant as it abounds in the cooler aspects of the marvellous rock garden in the Munich Botanic Garden. The foliage of this species is fairly distinct with its bluish-green to grey-green hue. There are now a whole range of modern hybrids, many of which are proving quite hardy and clearly possess the benefits of “hybrid-vigour”. These include: H. x ericsmithii ‘Winter Moonbeam’ with attractive foliage and white flowers that gradually fade to pink and the much sought-after H. x belcheri ’Pink Ice’.

Availability:

Ashwood Nurseries, www.ashwood-nurseries.co.uk

The Beth Chatto Garden, www.bethchatto.co.uk

Leave a Reply

Your e-mail address will not be published. Required fields are marked *