Controlling Canada goldenrod is important when managing for bio diversity. The goal is to minimize its presence so it doesn’t create a monoculture. As a native plant, it has value to insects and other wildlife.
Canada goldenrod (Solidago canadensis) is a native to Wisconsin but isn’t a highly prized prairie plant. Its Coefficient of Conservatism is a 1; making it essentially a glorified weed. It’s often confused with Missouri goldenrod (Solidago missouriensis) and sometimes with Showy goldenrod (Solidago speciosa).
Regardless of how careful you are to keep this out of your prairie, it will show up. It loves disturbed ground and spreads quickly via rhizomes. After a mowing or a burn Canada goldenrod is often be the first plant colonizing this area or will spread further. There is some speculation that it is allelopathic and that it does not allow the germination of other seeds. It also is long-lived; a stand in Iowa was thought to be over 100 years old. Its rhizatomous growth and clonal habit makes it difficult to control but its tendency to crowd out desirable plants and create a monoculture means controlling Canada goldenrod is important.
If you have a small area, this control method works well.
Here’s a video of a variation of the method for small areas.
If you have acres of it, this mowing method is effective.