Converting Non-Native Roadsides to Native
Table of Contents
Occasionally a landowner will contact the county IRVM program to request a native planting adjacent to his/her property. If the site is conducive to a successful native planting, some counties accommodate these requests. Converting non-native vegetation to native requires eliminating the existing vegetation, usually by application of glyphosate. Cool-season grasses such as brome, fescue and bluegrass can be persistent and might require more than one application.
- Kill existing vegetation with a 2% solution of glyphosate in April or May.
- If thistles and other broadleaves are present, apply a Transline/Telar mix the fall prior to glyphosate in the spring.
- Apply the herbicide when existing vegetation is green and growing but no more than 12 in. tall.
- If there is still green grass after ten days, apply the herbicide a second time.
- Consider keeping the top 4 ft. of the foreslope unsprayed, leaving it stabilized with mowable, cool-season grasses.
- A native grass drill is most effective for planting into the dead stubble, disturbing the dead turf as little as possible while getting seed in direct contact with soil.
- Keep the entire planting mowed during the first growing season because weeds will likely be released once the existing cover has been destroyed.
- In subsequent years, spot-spray weeds as they appear.
Establishment Mowing
During the first growing season, native seedlings remain small and can suffer losses due to competition by tall, thick weeds.
- Mow the planting three or four times during the first growing season.
- Don’t wait until the weeds are too tall.
- A mowing height of 4 in. is good but to avoid scalping, 8 in. is better.
Evaluating New Plantings
First-year native seedlings are small, making them hard to find and even harder to identify. As a result, people often worry or assume the planting is a failure.
- If the site was drill-seeded, look for anything growing in rows.
- Seedling ID books are available (see "Print Resources for Roadside Managers" in the Appendix).
- If the success of a seeding is being challenged, hire a botanist to look for seedlings.
- Unless a planting is washed out by heavy rains, allow two full growing seasons before giving up and starting over.