Purple Loosestrife

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Purple Loosestrife. Submitted photo

A campaign to raise awareness of and control invasive plants sponsored by Granby’s Conservation Commission

Purple Loosestrife – Lythrum salicaria ­—is October’s Invasive of the Month. Here is how to identify it, and what to do about it.

Find it

Its brilliant purple flowers in late summer through fall make it easy to identify this plant, which is several feet high and one–two feet wide. It grows in wet areas, wetlands and near ponds and waterways. It tolerates a wide range of soil. It prefers full sun but also grows in part shade.

Why it’s a problem

Once established, purple loosestrife may spread slowly for several years, until optimal conditions allow populations to explode. It then takes over, crowds out native species and wildlife food sources, and eventually leads to a loosestrife monoculture. It mainly spreads by seeds, transported by air, water, animals, boats and people. 

What to do

Do not plant it. All variants are invasive, even if they are advertised as not.

Remove it. Pull it out by the roots before it finishes flowering. Dig it out. Cut at the base. Dispose of it, without allowing seeds to disperse. Do not compost.

Control with beetles. UConn supports biological control of purple loosestrife using Galerucella leaf-eating beetles, which are beneficial insects that feed almost exclusively on this one plant. Beetle control is a very successful strategy that takes several years to achieve full effect. Anyone can raise and release the beetles and monitor their impact over time. The beetle is very susceptible to pesticides. For information on Galerucella beetle and information about becoming a Beetle Farmer, search for Purple Loosestrife at UConn.edu.

More information on Purple Loosestrife and the NOT WANTED campaign will soon be available on the Granby Conservation Commission webpage.

Purple Loosestrife. Submitted photo