Ragweed arrived in Europe from North America as early as the mid-19th century. The plant colonizes fallow land, disturbed areas, road or railroad verges, gravel pits, construction sites, agricultural land, but also private gardens. In Austria, it has been spreading for years and has long been naturalized in the warm lowlands in the east and southeast of the country. As a result of climate warming, its distribution area will increase, and an increased spread to other parts of Austria is to be expected.
Particularly unpleasant for allergy sufferers is the plant's late blooming period from July to October. A single plant can produce between 3,000 and 60,000 seeds, which can remain germinable in the soil for several years. Individual plants (e.g., in home gardens) should be pulled out, including the roots if possible, before flowering and disposed of in sealed trash bags with household trash.