Iowa Mowing Law for Roadsides
Mowing and Native Vegetation
Native plant restoration is an important part of IRVM, which is used by the Iowa DOT and many Iowa counties. IRVM includes the planting of native plants in the right-of-way, judicious use of herbicides, selective mowing, mechanical tree and brush removal, and the prevention and treatment of erosion. Because Iowa Code 318.3 prohibits the destruction of plants placed within the right-of-way, it is illegal for landowners to mow plants that have been planted by the state or county as part of an IRVM program. The state or county is responsible for mowing and managing these native plants.
Iowa Mowing Law
Iowa Code 314.17, which includes county secondary roads as well as state primary and interstate highways, extends the existing no-mow period, now from July 1 through July 15 to provide an additional two weeks for hatching and development of young ground-nesting birds and pollinators.
- Within 200 yards of an inhabited dwelling
- On right-of-way within one mile of the corporate limits of a city
- To promote native species of vegetation or other long-lived and adaptable vegetation
- To establish control of damaging insect populations, noxious weeds and invasive plant species
- For visibility and safety reasons
- Within rest areas, weigh stations and wayside parks
- Within 50 feet of a drainage tile or tile intake
- For access to mailbox or for other accessibility purposes
- On right-of-way adjacent agricultural demonstration or research plots
Mowing and Weeds
Because some noxious weeds and invasive plant species are best controlled by mowing early in the growing season, one of the mowing law expectations allow targeted mowing of noxious weeds and invasive plant species before July 15. For example, one effective technique for controlling invasive wild parsnip is to mow around the bolting stage in mid-May to early June. However, mowing after weedy or invasive plants have gone to seed [after mid-June for wild parsnip] can actually spread the plants and do more harm than good. Contact your county weed commissioner for more information on weed identification and appropriate method to control noxious weeds and invasive plants. Also contact your county engineer or roads side manager to ensure you are not mowing native pants that have been planted as part of an Integrated Roadside Vegetation Management(IRVM) program.