Rosebay Willowherb

Common Name

  • Rosebay willowherb

Latin Name

  • Chamerion angustifolium

Habitat & Distribution

  • Rosebay willowherb can be found throughout the UK, it is a native species commonly found in open spaces and clearings in grasslands, farmlands, roadside verges, woodlands and gardens.

What’s the problem?

  • Rosebay willowherb is a rhizomatous perennial species which can quickly colonise bare and disturbed grounds.
  • The plants spread via seed and also via horizontal rhizomatous roots which produce buds and new shoots. Established colonies can persist for many years.

In Detail

  • Seeds have hair like structures which aid wind dispersal enabling them to travel large distances. Each plant can produce around 80,000 seeds per year.
  • Plants are shallowly rooted. Within dense colonies the plant is mainly spread through horizontal roots which can spread up to 1m per year.
  • Although it can be invasive, the pink flowers provide a pollen and nectar source to a range of insects in the summer months.

Identification

  • Rosebay willowherb typically grows to a height of up to 110cm.
  • Leaves are alternate, growing spirally up the stem, they are lance shaped and narrow.
  • Flowers are pink in colour and are present from June to September.
  • Seeds have hair like structures giving them a fluffy appearance, these structures aid wind dispersal.

Control Methods

Mechanical:

  • Plants can be dug out but it is essential that all the rhizome is removed. If rhizome fragments are left they can produce new plants and potentially make the problem worse.
  • Repeated cutting several times a year over a number of years can reduce the infestation.

Chemical:

  • Infestations can be effectively treated with herbicide whilst the plants are actively growing between April and October. Additional applications may be required later in the year.

    If you would like a quotation for control, please contact one of our specialist surveyors. Treatment costs start from £380.00 + VAT.