; Purple Loosestrife - Finn Slough
Learning Center
Plans & pricing Sign in
Sign Out
Your Federal Quarterly Tax Payments are due April 15th Get Help Now >>

Purple Loosestrife - Finn Slough


  • pg 1
 The Beautiful

Sharon Gillies +
 Alida Janmaat
                        Purple loosestrife is
                        easy to identify
                        when in blossom.

Lessoning Loosestrife
               Winter                    Spring

Fall                                         Summer

       Hard to ID the rest of the year
• Introduced as a horticulture plant, it has
  become a problem in many areas.

• In the summer of 2007 an extensive
  survey of Langley, Abbotsford and
  Chilliwack was conducted to GPS map
  the distribution and abundance of
  purple loosestrife (Lythrum salicaria L.)
                               Purple Loosestrife
                                Where does it live?
                                                            • Moist soil to shallow water
                                                                  –   Wet meadows and pastures
                                                                  –   Marshes and wetlands
                                                                  –   Stream and river banks
                                                                  –   Lake shores
                                                                  –   Roadside ditches
                                                            • Can tolerate drier
                                                                  – Lawns and gardens
                                                                  – Agricultural and pasture
      Spreading in the Fraser Valley
Our survey found purple loosestrife
  in wetlands sites which had been
  disturbed by human activities
  (dredging, etc.).

When compared with a survey
  completed in 1992 where 7 sites
  were identified in this area, we
  found 108 purple loosestrife sites.

We did not find any large single
  species stands of purple

Problem areas in the Fraser Estuary – in particular in
brackish areas.
                  Purple Loosestrife
                    What does it do?
• Invades wetlands
   – Out-competes and replaces native plants
   – Eliminates natural food and cover for wildlife
   – Can change the structure and function of a wetland

• Affects humans
   – Can clog irrigation systems

• Possible uses
   – Provides a nectar and pollen source for bees

                                                    www.uq.edu.au/nanoworld/ images/honeybee-1.jpg
 Crowding out native
    species in BC?
In our study, 18 species
could only be found in
areas where purple
loosestrife was not present.

Our data may indicate that
some species are rare in
disturbed wetland sites, and
the presence of purple
loosestrife may increase
their rarity.
• The ability of purple loosestrife to crowd out
  native species may put some species at risk.

• We should remove it from wetland areas and
  prevent the spread of this invasive plant
                Purple Loosestrife
              How can we control it?
• Manual (digging, pulling,
    – Not effective for large
    – Difficult and time consuming.
      Must follow up annually when
      new plants appear.
    – Remove as much of root system   Cutting Stalks
      as possible and dispose of      Credit: MJ Kewley
      plants properly                 Org: Great Lakes Indian Fish &
                                      Wildlife Commission (GLIFWC)
                    Purple Loosestrife
                  How can we control it?
• Biological Control
   – Best for severe purple loosestrife infestation
     (>3 acres)
   – Works by using a plant’s natural enemies
     against it
      • After years of testing to be sure the species would
        not negatively impact wetlands and agricultural
        crops, three species [imported from Germany!]
        were approved for use in control of purple
           – Hylobius transversovitta tus, a root mining weevil
           – Galerucella calmariensis and Galerucella pusilla ,
             two leaf eating beetles
           – Nanophyes marmoratus , a flower feeding weevil

                                               http://www.ducks.ca/purple/faq/index.html - No.4
               Purple Loosestrife
           What can we do to help?

• Report locations where purple loosestrife is found
   – BC Report-A-Weed
   – http://www.for.gov.bc.ca/hra/Plants/raw.htm

• Request your local garden center or nursery to stop
  selling purple loosestrife if you find it there

• Replace purple loosestrife with native plants in
  ornamental gardens
• Alida Janmaat is conducting research on
  biological control of purple loosestrife in the
  Fraser delta.

• Sharon Gillies, Alida Janmaat, and Steve
  Marsh are collaborating by measuring water
  quality in the Fraser River as part of the
  Woods Hole Oceanographic Institute’s Global
  Rivers Project
• http://www.whoi.edu/page.do?pid=19760

To top