Black Horehound

©Anne Tanne

Black horehound

Scientific name: Ballota nigra
The pungent, rotten smell of Black Horehound makes this medium-sized plant of waste ground and roadside verges stand out from the crowd.

Species information


Height: up to 50cm

Conservation status


When to see

June to September


Black horehound grows along hedgerows and roadside verges, and on waste grounds. It is a common, perhaps unremarkable, plant with one defining feature - its pungent, rotten smell. This smell, particularly apparent when the leaves are crushed, keeps herbivores away and gives it a local name of 'Stinking roger' in some places. It flowers between June and September.

How to identify

Black horehound has hairy, oval or heart-shaped leaves, with toothed edges, that may turn black after the plant has flowered. The pinky-purple, 'hooded' flowers are arranged in whorls around the top of its stems.


Mainly found in England and parts of Wales.

Did you know?

Black horehound has a long tradition in herbal medicine and has been used to treat a range of issues from respiratory problems to travel sickness, depression to gout.

How people can help

Although they might not look especially wildlife-friendly, our roadside verges, railway cuttings and waste grounds can provide valuable habitats for all kinds of plants and animals. The Wildlife Trusts are involved in many projects to make these places as beneficial for wildlife as possible. We have a vision of a Living Landscape: a network of habitats stretching across town and country that allow wildlife to move about freely and people to enjoy the benefits of nature. Support this greener vision for the future by joining your local Wildlife Trust.