Mombretia / Crocosmia

We have a patch of these flowers in our orchard. They are very beautiful but apparently, they are a non-native invasive weed, originally from South Africa.

See below information taken from

It says this is one plant that perhaps it is best to use chemicals to treat or if you dig it out you should take it to a licenced landfill. Sounds so serious for such a pretty flower. We want to keep our orchard organic so won’t be using chemicals and when we discussed it with our community group most felt that as long as we don’t let it spread, it hasn’t so far in the few years we have run the orchard, surely we (and the bees) can just enjoy the flowers.

Common Name: Montbretia
Latin Name: Crocosmia

What’s the problem?

  • Monbretia is non-native species which can quickly out compete native plants forming dense clusters of growth.
  • The plant spreads by rhizomes and rarely by seed.
  • Legal implications if allowed to spread onto neighbouring land.

Legal Implications?

  • Listed as a Schedule 9 species under the Wildlife and Countryside Act 1981.
  • It is an offence to plant or allow to spread onto adjacent land and into the wild.
  • Possible fines and prison sentence under the Wildlife and Countryside Act 1981.
  • It is not an offence to have Monbretia on your land and you do not need to notify anyone on the presence of this species.
  • Soils containing Monbretia are classified as controlled waste and should be disposed of at licensed landfill.

In Detail

  • Monbretia is a hybrid of species originating from South Africa, the hybrid was first introduced from France to the UK in 1880 as a garden plant, escaping into the wild in 1911. It quickly spread throughout the 20thCentury.
  • Once established the species can dominate areas outcompeting native flora.
  • Bulblike organs called corms provide the plant with energy, the plant is able to regenerate from this material.
  • The plant is widespread over much of the UK but more common in western areas.


  • Smooth upright bright green leaves less than 3cm wide are present from spring to autumn, these form dense stands which can cover large areas. The plant grows to 60cm tall.
  • During the winter leaves die and are brownish in colour, with dead flowering stems and seed heads.
  • Flowers are orange in colour forming nodding clusters.
  • Corms are present underground at the base of the plant, and can be used to identify the species from other similar looking plants.

Control Methods

  • Plants can be dug out but it is essential that all the plant material and corms are removed. If corms are broken up or accidentally left they can produce new plants potentially making the problem worse.
  • Excavated material should be removed from site to licensed landfill as controlled waste.
  •  Chemical: When treating large areas, a suitable grass and forb mix should be sown to prevent bare ground and colonisation of other unwanted species. Infestations can be effectively treated with herbicide whilst the plants are actively growing