Eco Plant Whisperer – April 2023

Helleborus – Orientalis

It's just not easy to spot an entire Hellebore plant at this time of year that doesn't display the fungal signs of black spot on the leaves. Helleborus orientalis the Lenten rose seems particularly susceptible as with  the caulescent species of Hellebores.

Hellebores do of course display beautiful leaves, and if we as gardeners can keep them on the plants during winter, all the better. Often is the case though I find myself denuding the plant of most of the leaves with the secateurs, that it's just not worth leaving the small amount of good leaves on, leaving  a sparse display and not aesthetically pleasing !

It also has to be said too, that a group of Hellebores, particularly Orientalis, look quite stunning with all the black spot leaves removed displaying just the upright stems and stunning flower heads. I've undertaken this over the winter in a border of Helleborus orientalis at the Lakeside Garden.

It really is a task to keep cracking the whip at, even this time of year ! getting the best possible display into spring creates a brilliant transition for continuity of form, structure and flowers in the perennial garden.

Black spot is the most damaging disease on Hellebores and is caused by the fungus Microsphaeropsis hellebori. Black and brown blotches appear on the foliage, this increases and results in dead areas on the leaves. If this is left untouched and not removed, the stems and flowers can be affected, with various areas of the plant turning yellow.

The affects of black spot on the taller stemmed species of Hellebores is often triggered at the base of the plants during winter, this causes stems to severely rot before they have chance to mature. I have encountered this working for clients with Hellebores left out in pots, bought to plant. I immediately cut away the infected stems, right down to a basal growth, and lift into a glasshouse to recover, prior to planting out in the spring.

It's certainly a case of remaining very vigilant as often bacterial infections can result as a secondary infection to the black spot fungus, this can cause the basal areas of the plant to break down further. The disease is very prevalent in mild wet conditions. I am now acutely aware having gardened in the South Lakes for just over 6 years, the marked difference in more black spot on Hellebores compared to gardening in the Cotswolds.

Pulling away from the subject of plant diseases. The Hybrid Hellebores I planted within  the fringes of the semi woodland garden at the Lakeside  in the late autumn of 2021 are really coming into their own this year.

I have found that with any woodland garden planting of Hellebores, they really prefer a position of being planted on  the margins with just a bit of dappled shade, and some early morning winter sunshine filtering through the framework  of trees, as opposed to being planted within the setting of trees.