Noxious weeds in Ontario
Learn about the plants included in the Weed Control Act and what to do if you find them on your property.
Overview
A noxious weed is a plant that has been listed in the Schedule of Noxious Weeds found in Regulation 1096 made under the Weed Control Act.
In general, a species designated as a noxious weed under the Weed Control Act is one that:
- is difficult to manage on agricultural land once established and will reduce the yield and quality of the crop being grown
- negatively affects the health and well-being of livestock
- poses a risk to the health and well-being of agricultural workers
Purpose of the Weed Control Act
The intent of the Weed Control Act is to reduce:
- the infestation of noxious weeds that negatively impact on agriculture and horticulture lands
- plant diseases by eliminating plant disease hosts such as common barberry and European buckthorn
- health hazards to livestock and agricultural workers caused by poisonous plants
Noxious weed list
This list is commonly referred to as the "noxious weed list."
In Ontario, the following 25 weeds are designated as noxious under the Weed Control Act:
| Common Name | Scientific Name |
|---|---|
| Barberry, common | Berberis vulgaris L. |
| Bedstraw, smooth | Galium mollugo L. |
| Buckthorn, European | Rhamnus cathartica L. |
| Chervil, wild | Anthriscus sylvestris (L.) Hoffmann |
| Coltsfoot | Tussilago farfara L. |
| Crupina, common | Crupina vulgaris Cass. |
| Cupgrass, woolly | Eriochloa villosa (Thunb.) Kunth |
| Dodder spp. | Cuscuta spp. |
| Dog-strangling vine | Vincetoxicum rossicum (Kleopow) Barbar. |
| Dog-strangling vine, black | Vincetoxicum nigrum (L.) Moench |
| Goatgrass, jointed | Aegilops cylindrica Host |
| Hogweed, giant | Heracleum mantegazzianum Sommier & Levier |
| Knapweed spp. | Centaurea spp. |
| Kudzu | Pueraria montana (Lour.) Merr. |
| Parsnip, wild | Pastinaca sativa L. |
| Poison-hemlock | Conium maculatum L. |
| Poison-ivy | Toxicodendron radicans (L.) Kuntze |
| Ragweed spp. | Ambrosia spp. |
| Ragwort, tansy | Senecio jacobaea L. |
| Sow-thistle spp. | Sonchus spp. |
| Spurge, cypress | Euphorbia cyparissias L. |
| Spurge, leafy | Euphorbia esula L. |
| Thistle, bull | Cirsium vulgare (Savi) Tenore |
| Thistle, Canada | Cirsium arvense (L.) Scopoli |
| Tussock, serrated | Nassella trichotoma Hackel ex Arech. |
Local weed by-laws
A municipal council may, subject to the approval of the minister, designate additional plants as local weeds through a by-law. The by-law must be made in accordance with section 10 of the Weed Control Act.
These local weeds are deemed to be noxious weeds in the area where the by-law applies.
Noxious weeds on your property
You must destroy a noxious weed if:
- you are in possession of one of the weeds on the Schedule of Noxious Weeds
- it is negatively impacting agriculture and horticulture lands
If you feel that your agricultural or horticultural land is being negatively impacted by noxious weeds, contact your local Weed Inspector.
How to destroy noxious weeds
You can destroy noxious weeds by:
- pulling or removing the plants from the soil
- cutting the roots or stalks of the plants before the seeds have developed sufficiently to ripen after the cutting
- plowing or cultivating the soil in which the plants are growing
- treating with an herbicide that causes the plants to be destroyed or prevents the growth of the plants or the ripening of their seeds
Contact your local Weed Inspector
Find the Weed Inspector in your area by contacting either:
- your local municipality, region, district or county
- the Agricultural Information Contact Centre at
1-877-424-1300