Purple Loosestrife

Lythrum salicaria

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Purple Loosestrife – Erect squarish stems, up to 8 feet tall,
Leaves: 1 ½ to 4 inches long, lance-shaped and lack petioles, usually opposite and rotated 90 degrees from the previous node or whorled in sets of 3.

Flowers: spikes of magenta flowers 4 – 16 inches long, flowers from July to October.

Habitat: Found in wetlands and streams in the Centralia/Chehalis area as well as Stearns Creek and Mineral Lake in Lewis County.

Weed Classification: B designate

Why Is It a Noxious Weed?
Purple loosestrife is a vigorous competitor and can crowd out other vegetation including native species. It can quickly dominate a site and adapt to environmental changes that native species may struggle with. This weed affects flooding, erosion, salmon runs, salmon habitat, waterfowl coverage and nesting. The effects of purple loosestrife in irrigation canals on the east side of WA state has been extremely costly and detrimental to some crop farmers.

There are a few known infestations in Lewis County that we are directly addressing.

Control Recommendations:

WA State Noxious Weed Board
Pacific Northwest Pest Management Handbook
UC Davis Weed Report