Photo-National Invasive Species Center

Where are they from?

It was introduced in the 1800s form Europe, now it is present in all major watersheds across Pennsylvania.

Why are they so harmful?

Although it looks like a harmless pretty plant, this invasive is choking out our wetlands. One plant can produce over one million seeds with high germination rates. These seeds can travel on muddy boots, boats, boat trailers, and almost anything that gets in contact with the seed heads. New plants can grow from small broken pieces that get in contact with moist enough soil, making them very hardy. Loosestrife out-competes native wetland plants while having no value to wildlife. The cover that this plant provides is too dense, bird species have ignored wetlands that have become overrun by loosestrife. The expansive root system slows water through wetlands and promotes the deposit of sediment which can be costly to remove. Purple Loosestrife has no predators and has remained unchecked.

How can I identify Purple Loosestrife?

Use identifying apps like Seek by iNaturalist (On both Apple and Google Play stores).

When unable to use phones, remembering what the plant looks like from pictures and descriptions is best. The plant can grow up to 7 feet tall with purple/rose flowers along a spike. Flowers have 5 to 6 petals per flower. Leaves are long linear blades with smooth edges.

Where can I learn more?

Information Page by PSU Extension-- https://extension.psu.edu/purple-loosestrife-in-pennsylvania

Managing Purple Loosestrife by PSU-- https://plantscience.psu.edu/research/projects/wildland-weed-management/publications/working-lands-factsheets/purple-loosestrife