If left unchecked, purple loosestrife forms vast monotypic stands that will dominate an area and provide very little if any habitat for wildlife. An estimated 190,000 hectares of wetlands, marshes, pastures, and riparian meadows are affected in North America each year. This has an economic impact of millions of dollars. Because purple loosestrife is so widespread in the U.S., its total eradication is unlikely. However, the spread of purple loosestrife can be halted and newly invaded areas can be controlled.
Prevention is the best way to stop the purple loosestrife invasion.
Even Lythrum varieties advertised not to make seeds can cross-breed with the invading loosestrife to make seeds. Be on the look out for pioneering plants or isolated small colonies. Notify the proper authorities. If they occur on your own property, remove the plants or cut off the flower heads, bag and destroy them. Rinse equipment, gear, or clothing and footwear used in infested areas before moving to un-infested areas.