Purge The Spurge


Purge the Spurge – this is a phrase that you will become familiar with as you travel through the Qu’Appelle Valley near Last Mountain Lake. Leafy Spurge is an invasive plant that is native to central and southern Europe. It was transported to the United States in the 1800’s and has gradually and relentlessly spread to the more northern states, and finally into Canada. Leafy Spurge now occurs extensively in the southern Prairie provinces and southern Ontario. If not checked, this weed will continue to expand its range throughout Canada.

Leafy Spurge is a perennial plant that grows up to 1-1.2 m tall. It’s a bushy plant topped with clusters of small, yellowish-green flowers supported by distinctive heard-shaped bracts. The bracts appear in late spring while the actual flowers do not develop until late summer. Leaves are narrow and arranged spirally around the stem. Mature plants are about 1 m tall and have extensive horizontal roots. The entire plant contains a toxic, white, milky sap. This sap inhibits the growth of other plants in the infected area. The milky latex can also cause irritation, blisters and swelling in humans and is toxic to some livestock.

This plant thrives in natural prairie habitats and fields by usurping available water and nutrients and through plant toxins, prevents the growth of other plants underneath it. It is an aggressive invader that can completely overtake large areas of open land. Because of its persistent nature and ability to regenerate from small pieces of root, Leafy Spurge is extremely difficult to eradicate. The seed capsules open explosively, dispersing seed up to 5 m from the parent plant and may be carried further by water and wildlife. It reproduces readily by seeds that have a high germination rate and may remain viable in the soil for at least seven years. The spread from the root system reaches 8 m into the ground and 5 m across with numerous buds. As the Leafy Spurge plant is not native to Canada, there are no natural predators here.

Leafy Spurge is hard to control with chemical, ecological, or physical means. Biological control however, the use of insects, is an economical, long term solution to leafy spurge control. Specifically, the Aphthona genus flea beetle has had a significant impact on Leafy Spurge population.

Adult beetles are introduced into a spurge-infected area in early July where they eat the foliage and begin laying eggs. The eggs hatch and larvae feed on the weed’s roots through fall doing a great deal of damage to the plant. Feeding stops and the larvae create an over-wintering cell in the soil where they remain dormant. The larvae pupate and emerge as adults early the next summer to begin the cycle again. Once established in an area, the beetles can be collected and relocated to another spurge infected area.

When the Last Mountain Lake Stewardship Group (LMLSG) became aware of the presence of this dangerous weed in the Qu’Appelle Valley they acted quickly to implement a plan to control its spread. Darla Russell, an active member of the stewardship group, organized the Leafy Spurge Project. In July 2008 a team of volunteers traveled to southern Saskatchewan and collected a supply of the Aphthona beetle. The beetles were dropped in several locations near Last Mountain Lake that were heavily infected with Leafy Spurge. More beetles were collected again this year and dropped in these locations. A monitoring program has been established to observe the progress of the beetles.

The presence of invasive plants such as Leafy Spurge is a threat to our natural environment. Natural grass and wild flowers cannot compete with Leafy Spurge and these natural species will soon disappear from our landscape unless we do something about it.

The presence of Leafy Spurge in rangeland and pastureland has become a major concern to livestock producers as well, since it restricts grazing capacity for their livestock. LMLSG plans to expand this project to include ranchers and landowners who are presently faced with Leafy Spurge infestation.

Please do not assume that spurge infestation is restricted to open fields and grasslands. This weed has the ability to spread to villages, towns and cities in our province. You may see evidence of this weed in your own garden or back yard. If so, please contact the Noxious Weed Specialist in your area.

LMLSG has received funding for this project from Sask Watershed Authority and The Native Plant Society. This stewardship group is determined to “Purge the Spurge” and continue their commitment to protect the natural environment surrounding Last Mountain Lake. For more information on this project and others, please visit their website at www.lmlsg.ca