Picture this — a tall and slender green plant with elegant magenta flowers.

It is plentiful this year, observed on roadsides for the last couple of weeks and usually through early September is purple loosestrife (Lythrum salicaria).

The downside is it’s noxious. This invasive plant can be controlled but not eliminated. Highly adaptable, it thrives in damp to wet soils in our waterways but also grows in drier soils and sunny areas.

A native of Europe, it entered the country in the 1800s, possibly by ships carrying cargo and spread across the country. Currently, it is found in the Northeast and southern Canada but continues to spread around Lake Erie down to the Ohio River. The central U.S. is noticing it more frequently.

Growing 2 to 6 feet tall on branched stems with fine hairs, its roots are thick and the rhizomes, underground roots form new plants, edging out native plants our pollinators need. Purple and pink showy flowers bloom on terminal spikes that contain thousands of tiny seeds dispersed by wind, animals rubbing against the flower or carried by water if growing near a waterway.

This perennial has two to three leaves on the lower stem and smaller, alternate leaves at the top, attached directly to the stem. At 4 to 6 inches long, the leaves are hairy and lance-shaped; however, the base leaves are heart-shaped. In autumn, these leaves turn a scarlet red before falling off.

This invasive and densely growing plant pushes out native plants.

According to North Carolina State University Extension, it is against the law to sell or plant purple loosestrife because of its ability to replace native vegetation essential for waterfowl and pollinators.

In 36 states, it is considered a noxious weed. According to Ohio State University Extension, purple loosestrife clogs irrigation systems, and it is not uncommon to find 1 to 2 million seeds produced by only one plant, which can survive for several years in soil before sprouting.

Examples of problems are the songbirds that do not feed on these seeds and waterfowl that avoid these areas as they are too dense for nesting.

Penn State describes it as, “dense roots and leaves choking waterways, slowing the natural flow and promoting silt deposits.”

The economy suffers and will be affected adversely if this plant is allowed to degrade the water quality at this rate. Unfortunately, this plant has no natural enemies and can never be completely eradicated but can be controlled.

Fortunately, ways exist to prevent purple loosestrife from invading areas. Never planting or moving this plant is important. You can dig the plant, including new shoots and discard it safely before it starts blooming. Or, you can cut off the flowers before seeds form. Only professionals should use herbicides, especially around waterways, to prevent drift.

This aggressive plant, although lovely when blooming, is, unfortunately, spreading all too quickly, crowding out and killing native pollinator plants that bees, birds and butterflies need. Do your part to help control it.

For more photos and details about this invasive plant in our area, go to https://go.osu.edu/loosestrife.

Kane Shipka is an Ohio State University Extension Master Gardener Volunteer in Mahoning County.