Story County IRVM manages roadsides for invasive and noxious weed species, an important aspect of land management. Noxious weeds left uncontrolled can cause severe environmental and economic loss.

Story County values responsible use of herbicides. Spraying is done by applicators certified by the Iowa Department of Agriculture and Land Stewardship, promoting safe use of pesticides. Spraying equipment is calibrated throughout each spray season and used with herbicides that are registered by the EPA for use in roadsides.

Methods

Staff use herbicides to target and spot kill specific weeds largely through spot spraying. It targets specific weed problems like Canada thistle, musk thistle, giant ragweed and more. This technique is much more environmentally-friendly and cost effective than blanket spraying as was used in earlier decades.

Bare ground spraying is sometimes conducted to help maintain visibility around bridges, guard rails and shoulders. Special equipment is used to minimize off-target drift and only the minimal area needed to ensure motorist safety is treated.

Some areas cannot easily be sprayed for various reasons (slope, drainage, etc.). Controlled burns can aid in invasive and noxious weed management, as many weedy species are not fire-adapted. Mowing new roadside plantings can stimulate growth and reduce weed competition, as well as reduce noxious weed seed proliferation. 

No Spray Policy

Story County has a No Spray Permit available for landowners that are concerned about Story County spraying near sensitive areas adjacent to their property.