Mountain bluet ( Centaurea montana) David J. Stang

Mountain bluet

Centaurea montana

Description

  • Perennial herb with a taproot that grows between 30 and 80 cm tall.
  • Flowers have a purple-pink center surrounded by a blue fringe.
  • Flower heads have large, green bracts with dark brown edges.
  • Lower leaves are lance-shaped and grow up to 18 cm long.
  • Undersides of leaves have wooly hairs.
    Mature mountain bluet in bloom

Introduction and spread

  • Mountain bluet is commonly grown as an ornamental flower.
  • Native to the Mediterranean and Europe, it was likely brought here for use in gardens.
  • This species continues to be sold and shared today, which can introduce the plant to new areas.
  • Plants produce many seeds and can also spread by stolon. Plants can easily escape garden beds and invade a roadsides, forests and open fields. .
  • Illegal dumping of garden waste is an additional way that this plant can establish in natural areas.

Consequences of invasion

  • Mountain bluet can self-seed and colonizes quickly, making it very invasive. It can invade agricultural pastures and decrease food sources for livestock.
  • This species tolerates both dry and moist soils, allowing it to grow in many types of ecosystems. It is also able to grow earlier in the spring and later in the fall than native plant communities, giving it a competitive advantage.
  • Mountain bluet can outcompete native species, reducing biodiversity and forage available for animals.

Status in the CKISS region

  • There is insufficient information for this species on its distribution, impacts, potential for spread and/or feasibility of control. There is not yet enough information to assign a management category. CKISS plans to carry out inventory when possible, monitor known locations, and/or find out more information from other regions.
  • To learn more about how CKISS classifies and manages invasive species, see our Invasive Species Priority Lists page.

Integrated pest management options

  • Mountain bluet is a common horticulture purchase, so education for gardeners and horticulturalists is important. Be PlantWise and visit Grow Me Instead to choose non-invasive alternatives to mountain bluet.
  • Hand pulling, cutting, or mowing is effective before seeds have been produced.
  • Entire root systems should be removed to avoid re-sprouting.
  • This species has an extensive and long lived seed bank so follow up treatments may be required.
  • Some select herbicides are effective on this species.

Additional resources