Iowa DOT has two periods to allow harvesting of grass along highways
The Iowa DOT has established two time periods for harvesting grass within the state-maintained highway right-of-way.
* July 15 to September 1: For cool-season grasses and forage legumes (such as smooth brome, tall fescue, perennial ryegrass, alfalfa and birdsfoot trefoil).
* July 15 to August 15: For areas containing warm-season native grasses (such as switchgrass, big bluestem, little bluestem, Indiangrass, sideoats grama and Canada wildrye).
The Iowa DOT may restrict operations or define additional stipulations in the permit, including those that affect the health of the vegetation. Mowing of nurse crop or newly seeded areas that are not yet fully established will not be permitted. It can take four to five years following seeding for an area to become fully established.
Application for a harvesting and mowing permit is available from Iowa DOT
All work shall be performed between 30 minutes after sunrise and 30 minutes before sunset. Work performed between the road and ditch bottom requires traffic control. All personnel must wear approved safety apparel, which the Iowa DOT will provide for the applicant when the permit is approved.