The Gardener's Almanac

Hellebore Diseases

Hellebores are generally trouble free but in recent years some of the hybrids have been affected by various fungal diseases and viruses, e.g. Fungal leaf spot, Cucumber mosaic virus, Helleborus net necrosis virus.

 

 

• Fungal leaf spot; As the name suggests is caused by a fungus that causes brown elliptical blotches to appear on both sides of the leaves. Lesions can sometimes appear on the stems sometimes causing the leaves to shrivel and collapse.

 

The best cure is to remove all the affected parts, if the problem is only slight using a fungicide can sometimes help.

 

 

• Cucumber mosaic virus is transmitted by aphids and causes yellow to white line patterns to appear on the leaves.

 

As with all virus problems, destroy the infected plant/s immediately to reduce the risk of spread.

 

 

• Hellebore ’Black Death’

 

This is a relatively new disease that only affects hybrid hellebores.

 

It is seen as the blackening, distortion and stunting of the leaves and stems, and sometimes the flowers.

 

Black streaking and mottling appears as a ring spot pattern or in lines between the leaf veins.

 

These are eventually passed down the leaf stalks to the main stem of the plant.

 

An aphid endemic to hellebores is suspected of passing on the virus.

 

There is no cure for virus infection other than digging up all infected plants as soon as symptoms are noticed, and destroying them immediately to reduce the risk of spread.