Invasive Weeds:



Invasive or Noxious weeds are none-native plants that adapt quickly and aggressively to the Alberta landscape and cause lasting damage.  Unfortunately, there are many invasive weeds in Alberta and many are located around Lac Ste. Anne and Lake Isle.  There are two classifications of invasive weeds in the Alberta Weed Act: Noxious and Prohibited Noxious.




Noxious Plants regulated under the noxious category should meet the following criteria:

  • The plant can easily spread and have a substantial negative environmental, economic or social impact if allowed to do so.

  • The plant can be controlled at a reasonable cost.

  • Regulation is in the common interest of Albertans


Click here to see a list of noxious weeds spotted around our lakes.




Plants regulated under the Prohibited Noxious category should meet the following criteria:

  • The plant, if allowed to spread, will have a substantial negative environmental, economic or social impact.

  • If not present, the plant can be excluded at a reasonable cost.

  • If present, eradication is highly desirable and economically feasible.



There are at least two prohibited noxious weeds present at Lake Isle presently: Flowering rush and Himalayan Balsam.


Flowering Rush:

One of the main priorities of LILSA is the control and elimination of Flowering rush.  Please visit our Flowering rush page for more information on our petition and strategies to achieve this goal.



Himalayan Balsam:















Himalayan Balsam has recently been found on the south shore of Lake Isle and lac Ste Anne

.  The fact that it is classified as prohibited noxious means that upon identification of the plant it has to be completely removed and destroyed. The reason it's under this category is because the nectar is way more potent and also flowers longer than our native species, meaning our native plants won't get pollinated. The Himalayan has a very shallow root structure unlike our native plants that cover almost triple the surface area creating a better hold for the shoreline. This make them unsuitable for protecting the shoreline against ice heaving and repetitive wave action. When Himalayan has mature seed capsules they will actually explode when contacted sending thousands of seeds into the water which can stay viable for weeks. Himalayan Balsam is a pretty serious problem due to these three main reasons.

-Kelsie Norton, Nature Alberta


LILSA's approach to Himalayan Balsam is that we are hand pulling and bagging this prohibited noxious weed.  Our hope is to eliminate it from our shores within the next 3-5 years.  To do this we will need your help.  If you spot this weed on your property please remove it.  If you spot it along the shoreline or on public land please Contact Us to let us know of its location.


For the Alberta Invasive Species fact sheet on Himalayan Balsam click here.