All about Hellebores

Helleborus hybridus - often sold under its former name of Oriental hellebore (H. x orientalis) - is not classed as herbaceous, although at RHS Garden Harlow Carr, we generally remove the big, shiny palmate leaves for hygiene and tidiness. Hellebores will continue to produce leaves so there will be something to see on the bleakest winter’s day. Flowering starts early with the pure white Helleborus niger, commonly known as the Christmas rose, totally unfazed by the cold. After heavy frosts the flower stalks can be levelled to the ground; the blooms may be frozen, but don’t worry: as the temperatures rise sufficiently, the limp stems will recover. Hellebores are a wonderful garden plant providing real winter value. The flowers appear in mid to late winter but continue to keep a presence until late spring, with their glossy foliage on show for most of the year.

Most hellebores hang their heads to protect their pollen from the driving rain. There is, however, magic in turning up the flowers to investigate their hidden secrets: the spots and markings can be fascinating; the stamens clustered around the style and stigma form intriguing centres, designed to attract solitary bees which are scarce at flowering time and yet so essential for the pollination process.

Hybrid hellebores have several advantages over single species as they are hardier and more vigorous. There is also a greater diversity of flower colour and shape adding to the mix of species providing more choice in garden centres and nurseries. The colours of hellebore hybrids vary enormously and include pure white, pale yellow, apricot, pink, red and even blue-black. The petals can be a single colour, spotted or streaked. Dark hellebores are lovely close up but they tend to merge with the soil so require a contrast of a light background to uplight the flowers. The shapes of hellebore flowers are also varied, with double and semi-double varieties available to suit all tastes. They are, however, difficult to divide and don’t respond well to division. The best hellebores are produced as seed strains. It can take at least three years for a plant raised from seed to reach flowering.

There are other hellebore varieties each with their own charm: Helleborus arguitifolius, commonly known as the Corsican Hellebore and sometimes labelled as Helleborus Corsicus, produces clusters of rounded, apple-green flowers with handsome olive-green foliage with a serrated edge. Helleborus foetidus or the stinking hellebore is well worth a place in a woodland garden for its ability to flower in deep shade. The Christmas rose Helleborus niger can be difficult to grow in the garden. Their white flowers have short stems. You could try this hellebore in a container to help protect and keep the flowers crisp and fresh from the winter wet.

When investing in a hellebore make sure that it is in flower so you can see exactly what you are getting. Always look at the foliage and the vigour of the plant before purchasing. The leaves should be healthy and green, with no black markings. The flowering stems should be strong and sturdy with new growth shooting from the base.

The foliage of all hellebores can suffer from black spot disease called ‘Coniothyrium hellebori’ which shows itself by forming dark blotches on the leaf. The easiest way to avoid this disease is to buy a healthy plant. If the fungal black spots begin remove the infected leaves as soon as you spot a mark, dispose of them, but never add diseased leaves to the compost heap. As a preventative measure, you could apply a fine bark or compost mulch around each hellebore, this will help reduce the spores from being washed back up from the soil to the leaf by rain splashes. Take care not to cover the crown with mulch as this may cause rot.

Jobs for the week

* Cut back herbaceous plants

* Winter prune fruit trees

* Protect vulnerable plants from frost

* Continue winter digging as the weather permits.

With thanks to Tom White, Horticulturist at RHS Garden Harlow Carr

DIARY DATES

Until 26 Feb: Bath House Gallery & Library: Gardens Behind Barbed Wire A remarkable piece of World War One history is told in this exhibition. ‘Gardens Behind Barbed Wire’ tells the ‘forgotten’ story of an intrepid group of British men who set up a horticultural society in the Ruhleben internment camp in Germany and helped to feed their fellow prisoners throughout the War. Normal garden admission.

Saturday 28 - Sunday 29 January, 11am - 3pm: Grow & Show Weekend Join writer and broadcaster Martin Fish and a panel of gardening experts for a weekend of no-nonsense advice on how to grow your own fruit and vegetables. No matter what size of plot you have – from a window box to a spare bed or allotment – come along for practical talks and demonstrations. There’s also a chance to put your questions to the experts at a special grow your own Q&A. Normal garden admission.