People in the south of France are being asked to report and destroy highly allergenic ragweed plants to curb its spread before peak pollination period in late summer.
Native to North America, ragweed has small green-yellow flowers and should be removed if found on your own property or on public land.
This should ideally be done before the flowering period (between August and September) to avoid exposure to pollen, and gardening gloves and a mask should be worn. Make sure to remove the entire plant, including the roots.
Extreme cases can be reported via Signalement Ambroisie (Ragweed Reporting).
“When it comes to ragweed, effective management means early intervention… The earlier a report is made during the year, the more likely it is that the relevant authorities will be able to act in time,” states environmental research network, Fredon France.
The plant poses a threat to farming and biodiversity, and also causes some people to experience allergic reactions including rhinitis, conjunctivitis, swollen eyes, asthmatic reactions and rashes.
Estimates from the French Agency for Food, Environmental and Occupational Health and Safety (Anses) state that between one and 3.5 million people in France are allergic to ragweed and it is thought to cost between €59 million and €186 million per year in medical fees, including medication and consultations.
Which French regions are most impacted?
Ragweed is now present in all areas of metropolitan France, however the rate of proliferation varies greatly from one region to another.
In 2025, 67% of ragweed reports were made in the Auvergne-Rhône-Alpes region in the south-east of the country, according to the Fredon France annual report.
There has also been a growing number of reports in the neighbouring regions of Bourgogne-Franche-Comté, Occitanie and Nouvelle-Aquitaine.
Ragweed can grow rapidly and survive in a range of environments including agricultural plots, riverbanks, roadsides, construction sites, and wasteland.
The most common form of ragweed grows as a bush, and reaches around one metre high. It has fern-like leaves with small flowers, and a reddish stem.
It is sometimes confused with goldenrod as both plants grow in similar environments, however the latter has tall stems, simple elongated leaves, and bright yellow flower clusters that are far more distinctive than the smaller green-tinted ragweed blooms.
Goldenrod (pictured) has yellow flowers and relies on living creatures for pollination, while ragweed is pollinated by the windSergeMak/Shutterstock
For extreme cases, France’s Regional Health Agency asks the public to report ragweed on the Signalement Ambroisie website or application. You can alternatively email support-signalement@fredon-france.fr or call 01 89 70 52 98.
Over 6,400 alerts were received via this platform in 2025 - down some 8,000 from the previous year. Fredon France suggests this drop could be explained as there was not an online platform for users during part of 2025.
Most alerts were received in August, with reports being communicated to local prefectures who intervened to ensure safe and effective removal of the plants.
When filing a report, you will also be asked to indicate whether the plant’s leaves have been eaten by insects. You should add one or two photos to the report, if possible.
Bite marks could indicate the presence of the American Ragweed leaf beetle, a key ragweed predator that could help curb the spread of the weed.
