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Roadside Mowing Restriction Reminder

posted on 6/11/24


Now is the perfect time to remind Iowa residents and landowners of Iowa’s roadside mowing restrictions. The restrictions, which restrict the mowing of roadside ditches each year prior to July 15, are designed to protect nesting birds, monarchs, and pollinator habitat within the rights-of-way of state and county roads.


Delaying spring and summer mowing of roadside ditches allows songbirds and game birds to nest successfully in what is often their only limited available habitat.  June and early July are peak months for songbird and game bird reproduction.  Nests can be directly on the ground or attached to plants – including grasses and flowers within the road right-of-way. 


Landowners that voluntarily delay cutting or harvesting roadsides beyond the July 15 date will continue to protect late nesters, pollinators, and monarch butterflies.   Iowa DNR Upland Biologist, Todd Bogenschutz, estimated that 21% of pheasant nests may still be active on July 15th, dropping to 7 % on August 1st.   


Monarchs often lay eggs on milkweed found in roadside ditches.  Monarchs in Iowa will have up to three generations with the final migrating generation turning from chrysalises to butterflies in September and October.  Milkweed plants are essential for breeding and a variety of roadside flowers are vital to adult monarchs for feeding from spring through fall.  In some locations, roadsides provide the only available habitat where milkweed plants and flowers are left to grow.    


Pollinators like hummingbirds, honeybees, native mason bees, bumble bees, and other butterflies and moths all rely on roadside flowers for nectar sources.  In a state with highly restricted plant diversity and high chemical use, habitat with flowering plants is essential to the survival of many insect species. 


Although there are quite a few exceptions built into the Iowa law to allow for maintaining sightlines and for controlling unwanted weeds, cutting primarily for hay during restricted times, is not among the exceptions.  In addition, the Iowa State DOT roadsides require a permit for haying.

The Iowa law reads as follows:

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:

1. Within two hundred yards of an inhabited dwelling.

2. On rights-of-way within one mile of the corporate limits of a city.

3. To promote native species of vegetation or other long-lived and adaptable vegetation.

4. To establish control of damaging insect populations, noxious weeds, and invasive plant species.

5. For visibility and safety reasons.

6. Within rest areas, weigh stations, and wayside parks.

7. Within fifty feet of a drainage tile or tile intake.

8. For access to a mailbox or for other accessibility purposes.

9. On rights-of-way adjacent to agricultural demonstration or research plots.


It is also good to remember that native plant restoration is an important part of the IDOT and many counties’ Integrated Roadside and Vegetation Management (IRVM) programs.  Iowa Code 318.3 prohibits the destruction of plants placed in the right-of-way, including the mowing of 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 plantings.  If you are unsure if your roadside is a prairie planting project, contact your local county’s secondary roads office.  


You can help Iowa’s birds and butterflies by only mowing as needed and necessary, delaying haying or mowing for brush control until after July 15th, and delay blanket mowing of roadsides until after the middle of October.


To learn more about Iowa’s mowing laws, find out how you can help Iowa’s birds and butterflies, or discover what plants are in your roadsides please visit