Many ornamental invasive plants can be found in your flower beds or garden. These flowers are invasive plants because they spread rapidly, often escaping garden boundaries. They can outgrow native species, resulting in an impact on natural environments. They were added to the noxious and prohibited noxious weed lists under the Alberta Weed Control Act in 2010.

Image of the ornamental invasive plant purple loosestrife

Common ornamental noxious weeds:

  • Dame's Rocket (Hesperis matronalis)
  • Creeping Bellflower (Campanula rapunculoides)
  • Yellow Clematis (Clematis tangutica)
  • Common Baby's Breath (Gypsophila paniculata) 
  • Oxeye Daisy (Leucanthemum vulgare)

Common ornamental prohibited noxious weeds:

  • Himalayan Balsam (Impatiens glandulifera)
  • Salt Cedar (Tamarix spp.)
  • St. John's Wort (Hypericum perforatum)
  • Purple Loosestrife (Lythrum salicaria)

Use good gardening solutions

  • Learn the characteristics and spreading habits of the plants you wish to grow
  • Avoid all plants with known invasive behaviours (even if they are not listed on the Weed Control Act) such as goutweed (Aegopodium podagraria)
  • Read plant tags or catalogues – avoid plants with characteristics like ‘vigorous’ or ‘self sows easily’
  • Remove noxious plants as soon as possible even if they don’t look like they are spreading in your garden; their seeds can travel far distances and start an infestation at any time
  • Read the Alberta Invasive Species' Grow Me Instead brochure for great plant alternatives to noxious weeds 

Avoid wildflower mixes

Wildflower mixes often contain invasive plant species that spread rapidly and are not from the local area. Check the label for the scientific names to know exactly what you are planting in your garden and flower beds and avoid those that don't list species.

If you would like to plant wildflowers, it is best to research native wildflower species that are common to your area and plant individual flowers or purchase seed mixes from local reputable growers. 

I bought the plant at a greenhouse. Do I still have to remove it?

Yes, you will have to remove the plant. Some ornamental noxious weeds were only listed on the Alberta Weed Control Act in 2010. Some greenhouses are unaware that these plants are controlled by the Alberta Weed Control Act and continue to sell them to customers.

Please contact the County to let us know where you purchased the plant. Our inspectors can educate the retailer and their staff.

Other resources

Further information:

Last updated: Friday, February 17, 2023
Page ID: 38845