Poltava battle field is under the threat of being closed for visitors because of extremely high level of weediness. The most dangerous sort of weeds is ragweed (ambrosia), a summer annual plant whose growth height largely depends on the environment (the kind of soil, light, humidity, etc.) and may vary from about 30 cm to 1.5m. The highly allergenic plant pollen may cause symptoms similar to those of grass pollen allergy: running, itching nose; watery, swollen eyes. That is why Poltava City Council asked students from local institutes and colleges to take part in mass weeding on the Poltava Battle field. To stop ragweed spreading each plant must be pulled up by the roots that makes a fighting with ambrosia difficult and time consuming. The total square polluted by ambrosia in Poltava region is estimated to be app. 8,000 hectares.