State Distribution (28 / 50 states)
Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming
Listings by State
| State |
Classification |
Common Name Listed |
Notes |
| California | B | Canada thistle | |
| Colorado | Class C | Canada thistle | |
| Connecticut | Restricted | Canada thistle | |
| Delaware | Noxious | Canada thistle | |
| Georgia | Restricted | Canada thistle | |
| Idaho | Class B | Canada thistle | Restricted |
| Indiana | Terrestrial Invasive | Canada thistle | Perennial herb |
| Iowa | Noxious | Canada thistle | Perennial thistle |
| Kansas | Class B | Canada thistle | Restricted |
| Kentucky | Noxious | Canada thistle | Perennial thistle |
| Maine | Prohibited | Canada thistle | Do Not Sell List |
| Maryland | Prohibited | Canada thistle | Noxious |
| Michigan | Prohibited | Canada Thistle | Perennial forb |
| Montana | Priority 2B | Canada Thistle | Widespread |
| New Jersey | Noxious Weed | Canada Thistle | Prohibited seed |
| New Mexico | Class B | Canada Thistle | Perennial forb |
| New York | Prohibited | Canada Thistle | Perennial forb |
| North Carolina | Class B | Canada Thistle | Perennial forb |
| North Dakota | Prohibited | Canada Thistle | Perennial forb |
| Ohio | Prohibited | Canada Thistle | Perennial forb |
| Oklahoma | Noxious | Canada Thistle | Perennial forb |
| Rhode Island | Invasive | Canada Thistle | Perennial forb |
| South Dakota | Class 1 | Canada thistle | Perennial |
| Virginia | Tier 2 | Canada thistle | Perennial |
| Washington | Class B | Canada thistle | Perennial |
| West Virginia | Noxious | Canada thistle | Perennial |
| Wisconsin | Noxious | Canada thistle | Perennial |
| Wyoming | Designated | Canada thistle | Perennial |
Data compiled from individual state Department of Agriculture noxious weed lists.
Verify against current official state sources before regulatory use.
| U.S. Noxious Weed Database — generated April 2026.