IRVM was introduced to Iowa in the mid-1980s in response to the need for surface water protection. Prior to that time, roadside weed control relied on herbicides blanket-sprayed across the right-of-way. Besides being expensive and contributing to surface water pollution, blanket-spraying was ineffective. By weakening desirable vegetation and creating bare spots, weeds flourished.
The solution was an integrated approach to weed control using a variety of methods:
Strategic herbicide use
Replace blanket-spraying with spot-spraying, targeting undesirable species using the right herbicide at the right time.
Spot-mowing and prescribed fire
Properly timed, these weed control methods are effective.
Native vegetation establishment
Naturally adapted to tough roadside conditions, healthy stands of tall, deep-rooted native plants outcompete weeds.
The integrated approach to roadside maintenance now extends beyond weed control to erosion control, brush control and stormwater management – all relying, when practical, on the use of native vegetation.
The Benefits of Native Vegetation in Iowa Roadsides
- Native plants are durable, long-lived perennials well-adapted to Iowa’s climate and growing season.
- A diverse native planting adapts to a wide range of soil and moisture conditions.
- Extensive, native plant root systems provide superior erosion control. See our Prairie Roots Project for more.
- Deep roots and dense, above-ground foliage reduce stormwater runoff by intercepting raindrops, slowing water flow and increasing infiltration.
- Extensive roots and decaying foliage further increase stormwater infiltration by adding organic matter to the soil, making it spongier and more absorbent.
- Extensive root systems penetrate 6-8 ft. or deeper, enabling prairie plants to survive drought and high salt concentrations while depriving weed roots of water, nutrients and space.
- Tall prairie vegetation shades out Canada thistle and other weed seedlings.
- A wide swath of prairie grass in the right-of-way traps blowing snow.
- Native roadside plantings provide valuable habitat for songbirds, game birds, small mammals and pollinators.
- Native plants beautify the right-of-way in a manner that reflects Iowa’s historic prairie landscape.