Since 2005 the common ragweed, Ambrosia artemisiifolia, which was introduced from North America has also been found in Bavaria in larger stocks and has an increasing tendency to spread. After receiving the report of the Bavarian Ministry of Health, the Bavarian Parliament addressed the implications for health. There was consensus across all political groups to combat the plant. Under the auspices of the Ministry of Health the action programme “eradication campaign against ragweed” aimed at systematic control was set up in 2007 in cooperation with the Ministries of Agriculture (registration office at the State Research Center for Agriculture) and the Interior (district administration authorities). The 96 district administration authorities, which each have a trained ragweed officer, report to the registration office on new verified ragweed locations with more than 100 plants. The reports of common ragweed stands are filed by citizens or through research by the district administration authorities, who are also responsible for supporting the fight against stocks. On behalf of the Bavarian Ministry of Health, the Working Group Biodiversity monitors the situation and finds many new locations. Since 2006, 279 new common ragweed stocks were registered. After control measures there are currently 190 known remaining stocks. Since 2007, however, the populated area has tripled. This means that the control measures need further improvement. This is especially true for the common ragweed stocks along roadsides where the plants have increased massively in recent years. Sustainable control has proved to be particularly difficult.