The Linn County Secondary Road Department would like to remind residents, landowners and roadside maintenance crews of Iowa’s roadside mowing restrictions. The restrictions prohibit the recreational mowing of roadside ditches each year prior to July 15 in order to protect habitat and nesting within the rights-of-way of state and county jurisdictional roads.
There are some exceptions built into the law to allow for maintaining sightlines and for controlling weeds. Cutting for hay is not among the exceptions.
According to the Administrative Provisions for Highways in the Iowa Code, mowing roadside vegetation on the rights-of-way or medians on any primary highway, interstate highway, or secondary road prior to July 15 is prohibited, except as follows:
• 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 a mailbox or for other accessibility purposes.
• On rights-of-way adjacent to agricultural demonstration or research plots.
Benefits of the Mowing Restrictions
Iowa Code 314.17 was amended in 2010 and now includes county secondary roads as well as state primary and interstate highways. The legislation moved the “no-mow” date from July 1 to July 15 to provide an additional two weeks of hatching and development of young birds. Studies have shown a significant increase in nesting success (more nestlings ready to fledge) given this extra time. With the 2010 amendment to the law expanded to include county secondary roads, an additional 500,000 acres of vegetated right-of-way statewide are protected.
Studies show that for pheasants, 39 percent of nests are un-hatched by July 1 and likely destroyed with a July 1 mowing. By July 15, 22 percent of nests are un-hatched; so delaying two weeks allows an additional 17 percent of nests to hatch. Many songbirds nest in roadsides and stand to benefit from the law as well. Roadsides become even more valuable for habitat as high annual row crop prices reduce the number of acres enrolled in the Conservation Reserve Program.
In an intensely agricultural state such as Iowa, with little ground left otherwise undisturbed, the law serves as a reminder to those who do not need to mow their ditches to mow only the shoulder and leave the rest for the birds. Too much mowing weakens the native vegetation that Linn County is establishing in roadsides along secondary roads. And driving tractors on roadside slopes often tears up the turf thereby creating openings for weeds.