March 5, 2024
Ontario invasive plants
Landscape Ontario recognizes the threat of invasive plants to certain environments. Nursery production is focused on providing alternatives to potentially invasive plants wherever possible and nursery grower members are constantly evolving their production based on science.

LO supports the adoption of the CCIS code of conduct. The Grow Me Instead guide has useful information, however not all plants suggested can currently be produced en masse in a commercial setting, or transplant well in home gardens. Landscape Ontario members are constantly looking for new and improved plants that can replace invasives and that will perform well in a range of habitats.
 
link to powerpoint presentation

Prohibited invasive species

In Ontario, it is illegal to import, possess, deposit, release, transport, breed/grow, buy, sell, lease or trade prohibited invasive species.
 

Restricted invasive species

In Ontario, it is illegal to import, deposit, release, breed/grow, buy, sell, lease or trade restricted invasive species.
 

Exceptions for restricted species

Outside a provincial park or conservation reserve, it's not illegal to deposit or release a restricted species if you are:
  • Trying to manage or control it.
  • Working on your farm, in your business or doing maintenance.
If you deposit or release a restricted invasive species while undertaking any activity listed above, you must take reasonable precautions to prevent the spread of the restricted invasive species outside the immediate area where the activity is taking place.

Note: There are exceptions for prohibited species (found on the MNRF website), but generally it is only possible to move these species if they are dead and unable to reproduce. For example, preserved specimens for research or eviscerated/cooked for eating. If live specimens of prohibited species are found they must be destroyed immediately.

Prohibited invasive species (plants)

In Ontario, it is illegal to import, possess, deposit, release, transport, breed/grow, buy, sell, lease or trade prohibited invasive species.
 
ITEM COMMON NAME SCIENTIFIC NAME
1. Brazilian Elodea Egeria densa
2. European Water Chestnut Trapa natans
3. Hydrilla Hydrilla verticillata
3.1 Oxygen Weed Lagarosiphon major
4. Parrot Feather Myriophyllum aquaticum
5. Water Soldier Stratiotes aloides
6. Watermoss All species in the genus Salvinia
Source: O. Reg. 354/16, Table 2; O. Reg. 380/23, s. 6

Restricted invasive species (plants)

In Ontario, it is illegal to import, deposit, release, breed/grow, buy, sell, lease or trade restricted invasive species.
 
Item Common Name Scientific Name
1. Black Dog-strangling Vine Cynanchum louiseae
2. Bohemian Knotweed Reynoutria ×bohemica
3. Carolina Fanwort Cabomba caroliniana
4. Black Dog-strangling Vine Cynanchum louiseae
4.1 Eurasian Water-milfoil Myriophyllum spicatum
5. European Frog-bit Hydrocharis morsus-ranae
5.1 Floating Primrose-willow Ludwigia peploides
5.2 Flowering-rush Butomus umbellatus
6 Giant Knotweed Reynoutria sachalinensis
7. Himalayan Knotweed Koenigia polystachya
8. Japanese Knotweed Reynoutria japonica
9. Phragmites Phragmites australis subsp. australis
9.1 Tree-of-heaven Ailanthus altissima
9.2 Water Fern All species in the genus Azolla
10. Yellow Floating Heart Nymphoides peltata
Source: O. Reg. 702/21, s. 13; O. Reg. 380/23, s. 9.

Resources


Image courtesy Cassie Russell, OMAFRA