Thistle #417033 - Ask Extension

Knowledgebase

Thistle #417033

Asked July 26, 2017, 3:06 PM EDT

Is this thistle considered a beneficial wildflower in MN or an invasive species?

Adams County Minnesota

Expert Response

Your photo is too blurry for a proper identification - it could be bull thistle or Canada thistle, both non-native invasives. In general, the non-native thistles are much more prickly and spiny than the native ones.

The non-native thistles are mostly considered noxious weeds. Look here for a list. Click on any one and look at photos and identifying features.
https://www.minnesotawildflowers.info/search?kw=thistle

Read here for controls:
https://www.extension.umn.edu/garden/yard-garden/weeds/thistle-control/
Dennis White Replied July 27, 2017, 2:57 PM EDT

Loading ...