Rosebay willowherb

(Chamaenerion angustifolium)

Few plants are better at spreading than Rosebay willowherb. Gardeners who battle with it every year will not need to be told that. It is an expert coloniser and has succeeded in turning itself from a woodland rarity to one of the nation’s most common “weeds”. You do not have to try hard at all to find it in and around Killearn.

Rosebay willowherb is a tall perennial herbaceous flowering plant with red stems, lance-shaped leaves and pink flowers forming a spiky head.

It grows up to two metres tall and is common in fields, verges, gardens and waste ground, where it is often the dominant plant and grows in large colonies.

Fascinating fact:

Every rosebay willowherb seed capsule can release 300 to 400 seeds. That adds up to 80,000 per plant. And every seed has silky hairs to help it disperse on the wind.

Rosebay Willowherb was considered rare in Britain in the 18th century. But when thousands of “navvies” built the rail network with their bare hands, their hard work disturbed vast areas of ground and created the perfect conditions for the willowherb to spread and create new colonies. The plant also colonised the craters from Luftwaffe raids in World Ward II, so much so that people in south-west England call it bombweed.

People in the UK do not eat rosebay willowherb but other cultures dry it to make tea. Some people also believe it has medicinal properties. It has been used to try to treat digestive problems and even typhoid and cholera.

Did you know

Rosebay willowherb is the favourite food of the caterpillars of the Elephant hawkmoth. Look for them on the plants between late June and September.