Purple Loosestrife
Purple Loosestrife (Lythrum salicaria) is a wetland plant from Europe and Asia. It was introduced into the east coast of North America in the 1800s. First spreading along roads, canals and drainage ditches, then later distributed as an ornamental, this exotic plant is in 40 states and all Canadian border provinces. The plant can form dense, impenetrable stands that are unsuitable as cover, food or nesting sites for a wide range of native wetland animals, including ducks, geese, rails, bitterns, muskrats, frogs, toads and turtles. Many rare and endangered wetland plants and animals also are at risk. Purple loosestrife thrives on disturbed, moist soils, often invading after some type of construction activity. Eradicating an established stand is difficult because of an enormous number of seeds in the soil. One adult can disperse 2 million seeds annually. The plant is able to reproduce from roots and broken stems that fall to the ground or into the water. A major reason for purple loosestrife's expansion is a lack of effective predators in North America. Several European insects that only attack purple loosestrife are being tested as a possible long-term biological control in North America. Likely means of spread: Seeds escape from gardens and nurseries into wetlands, lakes and rivers. Once in aquatic systems, seeds are easily spread by moving water and wetland animals.


Distribution :
Purple loosestrife is now found throughout most of North America with the exception of Mexico, Florida and northern Canada. Currently, the area of greatest concentration and impact has been in southern Ontario, Quebec, New Brunswick and Nova Scotia and adjacent areas in the northeastern United States. The spread of this plant occurs primarily on disturbed soils of recently built roads, canals, railway lines and cultivated areas. It appears purple loosestrife thrives in areas of populated places with connecting roadways and degraded and disturbed wetland habitats. Purple loosestrife can also invade healthy wetland habitats and since seeds can be spread by water, it can spread within the watershed. Most of the isolated incidents of purple loosestrife have likely resulted from intentional introductions or escapes from ornamental gardens.
Control:
There are several management techniques for controlling purple loosestrife. The L.R.C.A. recommends hand pulling as the most effective method where appropriate. Herbicides are not recommended, as they will effect other species.
Hand pulling:
*Effective and selective
*Best done while plant is in flower (i.e. July and August) and before it goes to seed
*Loosen soil with garden fork or shovel; grasp plant firmly near the base and pull evenly to avoid detachment
*Plants should be dried, burned or put in garbages and disposed of in a sanitary landfill where there is no chance of spreading
Cutting:
*Used to contain large populations of loosestrife, by reducing stem numbers and seed production
*Care must be taken to gather up the cuttings
*Repeated cuts are required to eliminate the plant from the site
Biological Control:
*A long-term solution that will not completely eradicate, just reduce density of loosestrife
Involves releasing European insects that are predators of loosestrife
*Thorough scientific screening of potential species has resulted in a few being approved for release
*LRCA released Galerucella beetles at two sites near Thunder Bay in 1997 and at three sites near the Kam River in 2003. In 2007 beetles were released along the Thunder Bay Expressway near Dawson Road.
*At a release site east of Thunder Bay, the beetles dramatically reduced loosestrife plants to short withered stems within a few years.
Herbicides:
*In most areas is not permitted for general usage.
Must be used with extreme caution, because herbicides are non-selective and will hurt the nearby vegetation