Purple loosestrife is often associated with cattail, reed canary grass, and other moist soil plants. It has an incredible ability to out-compete native vegetation and to form dense stands. Furthermore, Purple loosestrife has no natural enemies in North America. Purple loosestrife's ability to spread contributes to its success as an invader. One loosestrife plant can produce millions of seeds annually.
Seeds are long-lived and easily dispersed.
Also, purple loosestrife plants are capable of resprouting from broken stems or roots. The plants have strong root stocks that serve as storage for spring regrowth and regenerations following natural or human disturbance. Finally, the commercial sale of purple loosestrife increased the spread of the plant by introducing it to various watersheds. Purple loosestrife is a problem because it negatively affects wildlife and agriculture. Purple loosestrife displaces and replaces native flora and fauna, eliminating food and shelter for wildlife.