Stop Knotweed

Asian knotweed is an invasive alien plant that poses a threat to local biodiversity

active volunteers in 2023
0
of knotweed eliminated by 2023
0 kg
of land treated in 2023
0 m2

This project is supported by theFederal Office for the Environmentthe cantons of Vaud and Geneva and the Electricité Vitale Vert Fund SIG.

The interreg project " Stop invasives "This project, to which the ASL contributed, has now been completed. The full final report and a summary can be downloaded at HEPIA website.

PLEASE NOTE: for company initiatives (corporate volunteering, team building, etc.), please complete the form below. form for voluntary work.

What is Japanese Knotweed?

Origin and description

Asian knotweed (Reynoutria japonica, Reynoutria sachalinensis, Reynoutria x bohemica) are invasive alien species that were imported from Asia in the 19th century as ornamental and forage plants.

They have a green stem reminiscent of bamboo and heart-shaped leaves with a slightly flat base. The nodes of the stems are often reddish.

When young, the stem and leaves are red.

The aerial part of the plant dries up in winter and the plant grows back in spring (plant geophyte).

Asian knotweed (Reynoutria japonica, Reynoutria sachalinensis, Reynoutria x bohemica) are species of invasive herbaceous perennials in the Polygonaceae family, native to eastern Asia and naturalised in Europe in a wide variety of wetlands.

These large, vigorous plants have upright, hollow, reddish stems resembling bamboo canes.

These are geophytic plants with an erect rhizome/hemicryptophyte. The broadly ovate-triangular lower leaves reach 15-20 cm in length and are abruptly truncated at the base. They alternate.

The small white flowers are arranged in panicles in the leaf axils.

Native to Asia, they do not suffer from parasites in our latitudes.

They grow very quickly (up to 8 centimetres a day and 3 metres in a few weeks), quickly taking over the whole area and overshadowing native plants.

Just 1 cm of stem or root is enough to re-grow a plant. It is therefore extremely easy to propagate, whether voluntarily or not.

Its trailing rhizomes allow massive regrowth after the winter and a good spread over the ground. It is therefore the first plant to regrow in spring, preventing native plants from finding their place.

The emission of toxic substances by the roots to limit the development of other plants.

Regular hand-pulling every 2-3 weeks during the growing season (April to October), for several years.

Get involved in the fight against this scourge!

Are you keen to get involved and help us in this long-term effort to combat the scourge of invasive plants? It's also a great opportunity to get out and about in the fresh air, do something healthy and meet new people!

You will be given all the information you need about the types of work you can do, the sites where you will be working and the times of year (April to October) when this large-scale operation will take place.

We therefore need all the help we can get to ensure that our work is carried out on a regular basis. We need everyone in the cantons of Geneva, Valais and Vaud, as well as in Haute-Savoie, to get involved in our "Halte aux Renouées" campaign.

The number of volunteers required for the various knotweed sites depends on the size of the sites and the state of the regrowth after our intervention.

If your town is not listed in the form opposite, please contact us!
gro.namelsaobfsctd@lsa or 022 736 86 20

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