Canada Thistle Research at Montana State University

This video shows trials at Montana State University, in which different forage crops and cover crops were planted to learn which were best at suppressing Canada thistle in spring wheat. This research was part of a USDA NIFA OREI funded research project: CREEP Stop: Organic Control of Canada Thistle and Field Bindweed in the Northern Great Plains and Pacific Northwest Regions, led by Patrick Carr of MSU. In the video, Dr. Tim Seipel, MSU Cropland Weed Extension Specialist and Nate Powel-Palm of Cold Springs Organics tour the trials and discuss how alfalfa helped suppress Canada thistle. They also discuss other organic strategies that can help control the spread of perennial weeds as part of an integrated weed management program. Video by Riley Slivka of Agristudios.
IMPORTANT: Before using any pest control product in your organic farming system:
read the label to be sure that the product is labeled for the crop and pest you intend to control, and make sure it is legal to use in the state, county, or other location where it will be applied,
read and understand the safety precautions and application restrictions, and
make sure that the brand name product is listed in your Organic System Plan and approved by your USDA-approved certifier. If you are trying to deal with an unanticipated pest problem, get approval from your certifier before using a product that is not listed in your plan-doing otherwise may put your certification at risk.
Note that, although OMRI and WSDA lists are good places to identify potentially useful products, all products that you use must be approved by your certifier.

[@0rganicall3Produced]

Thank you for this topic and discussion. I’m currently transitioning a farm from tillage to no-till. It’s overrun with thistle and bindweed. With a low budget my only defense has been to utilize cardboard and free wood chips to stop and/or reduce growth of both of these invasive plants. I’ve been planting into compost on top of the cardboard. Obviously once the cardboard breaks down enough the roots of the crops I’ve planted are able to puncture and grow larger but that is also the point where the bindweed finds sunlight and once again becomes a nuisance. The thistle seems to be controlled as long as I have dug it out or cut it off just below the surface prior to laying the cardboard, for now. Despite the entire three acres being covered with thistle and bindweed, I’ve noticed where I’ve been working, the continuation of these two invasive species seems to have been reduced by at least 90%.

[@coreyacre6070]

What if you have thistle in a older grass stand?

[@coreyacre6070]

So what is a good organic approach to killing thistle?