Invasive Species Council of British Columbia
Invasive Plant

Purple loosestrife

Lythrum salicaria

About This Species

Purple loosestrife (Spike loosestrife, Purple lythrum) is a perennial plant that spreads rapidly by seed and root fragments. It was introduced from its native range of Europe and Asia. The tiny seeds are dispersed by wind, mud, moving water, wildlife and humans. A mature plant can produce up to 2.5 million seeds that can survive in the soil for up to 20 years. Purple loosestrife grows in wetlands and aquatic habitats, as well in wet pastures and roadside ditches and is quite easily recognized by its flowers. Purple loosestrife is designated as a Provincial Noxious Weed by the BC Weed Control Act, as well as a Management species by the BC Provincial Priority Invasive Species List. 

How to Identify

Purple loosestrife has a shrub-like appearance, with stiff, four-sided stems. Plants can grow up to 3 m in height. 

Flowers grow in in dense spikes and are showy and pinkish-purple.  

It has narrow, stalkless leaves.  

Purple loosestrife is often confused with the native plant fireweed. 

Take Action

Prevention is the best approach.

Clean, Drain, Dry

Learn about best practices

The Clean Drain Dry program empowers you to help reduce the spread of invasive plants and organisms to BC waters by following the clean, drain, dry procedure on all watercraft and equipment.

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Learn about best practices



Learn about best practices

A few non-invasive alternatives to plant instead of Purple loosestrife include:


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