Purple loosestrife was introduced from Europe in the 1800s, and was once widely promoted for gardens, especially those with moist or wet soil, because it is an adaptable plant with beautiful, long-lasting pinkish-purple blooms that attract hummingbirds and a variety of other pollinating insects.
How does it spread?
Purple loosestrife spreads rapidly by seed and root fragments. The tiny seeds are readily dispersed by wind, mud, moving water, wildlife and humans. When disturbed, small fragments of stem or root can easily establish new plants wherever they are relocated. A mature plant can produce 30 to 50 stems, grow 2-3 m in height, and annually produce up to 2.5 million seeds that can remain viable in soil for up to 20 years.
Where would I find it?
Purple loosestrife is an extremely aggressive plant of wetland and marginal habitats, such as along lakeshores, ponds, wet pastures, and roadside ditches. It has been found growing in standing water and on drier sites such as cropland and pastures. This plant is common in the southwest of BC, especially on Vancouver Island and in the lower Fraser Valley as well as in the Okanagan. To a lesser extent, it can be found in the Kootenays and in the Quesnel region.
What problems does it cause?
Purple loosestrife spreads prolifically and has become a major threat to wetlands across North America. Dense, impenetrable stands grow to 2.5 m tall in both natural and disturbed areas, out-competing and replacing native species and impacting animal and bird habitat. Once firmly established in dense stands this plant can also impede water flows especially in irrigation channels.
- Wilson’s Ligularia (Ligularia wilsoniana) (z2)
- False Spirea (Astilbe x arendsii) (z4)