Weed Control

Weed Control

The Roadside Vegetation Management Department is also responsible for upholding the Iowa Weed Law (Chapter 317, code of Iowa) within Bremer County. Historically invasive species have always been a problem in the roadside, but the county Weed Commissioner oversees the control of noxious weeds on all public and private property. Controlling noxious weeds is an important aspect of responsible land management. If noxious weeds are left uncontrolled they can cause severe economic and environmental loss. Weeds may be controlled in the following ways:

Spot Spraying

A technique that uses herbicides to spot treat weeds. Specific weed problems like Canada thistle, musk thistle, and giant ragweed are targeted. The selected herbicides used are effective, yet environmentally sensitive. In the past, blanket spraying killed or stressed many plants in the roadside resulting in weedy vegetation and water quality issues. It was also very expensive.

Controlled Burning

Requires proper weather conditions, equipment, and management skills. Rotational burning at the right time can boost native vegetation historically linked with fire to promote growth. Many weedy species are not fire-adapted.

Mowing

Used to reduce seed proliferation, improve site distance at intersections and signs, and to reduce snow drifting. Limited mowing also decreases equipment maintenance, fuel requirements, and labor costs.


A healthy and diverse native planting can be relatively weed resistant. To promote healthy plantings, IRVM uses a diverse native seed mixture and limits disturbance in the right-of-way. Disturbance concerns include: off-label herbicide use (overspray), excessive water movement, encroachment, and soil erosion.