Spear Thistle

Common Name

  • Spear thistle

Latin Name

  • Cirsium vulgare

Habitat & Distribution

  • Spear thistle can be found throughout the UK. This native species is commonly found on disturbed grounds, farmlands, road side verges, and gardens. It thrives is soils of high fertility.

What’s the problem?

  • Spear thistle can quickly spread via seeds which are dispersed by wind.
  • Spear thistle is an injurious weed species and is listed under the Weeds Act 1959.

Legal Implications?

  • The Weeds Act 1959 aims to prevent the spread of listed species onto private land (Ragwort, Broad-leaved Dock, Curled Dock, Creeping Thistle, and Spear Thistle).
  • The Act allows for powers of enforcement requiring land occupiers to take action to control infestations to prevent the spread of Injurious Weeds onto neighbouring land.
  • Failure to comply with enforcements can result in penalties and convictions.

In Detail

  • Plants form a deep branched taproot in the first year providing good anchorage into the ground.
  • Seeds are air borne and readily germinate in warm weather. Each seed head can produce around 100 seeds.
  • Although the species can be invasive, seeds are an important food source for a range of farmland birds including linnets and finches.

Identification

  • Spear thistle is a tall biannual species, the flowering stem typically grows to 30cm – 1m in height usually in the second year.
  • Leaves are deeply divided with lobes terminating in a sharp spine. The upper surface of the leaf is rough and hairy.
  • Flowers heads appear from July to September with lilac-purple florets.
  • Seeds have a downy pappus which aids wind dispersal. The flower stems die back after producing seed.

Control Methods

  • Chemical Control

Spear thistle can be successfully treated with herbicide, applications are most effective whilst the plant is actively growing between April and October. Established infestations may require treatment over a number of years to ensure the seed bank is depleted.

  • Mechanical Control

Infestations can be weakened by repeated cutting over a number of years before the plants produce seed.

If you have concerns over Spear thistle on your land, if you are unsure of your legal responsibilities, or if you would like a quotation for control, please contact one of our specialist surveyors. Treatment costs start from £380.00 + VAT.