Invasive and Noxious Weeds

What are Noxious Weeds and who Controls them in Dallas County?

Noxious weeds are weeds that, required by law, must be controlled.  In Iowa they consist primarily of invasive weeds, but do include two native species that can be troublesome in agricultural settings.  Not all invasive weeds are declared noxious.  Iowa's Noxious Weed list and law can be found here.

Canada thistle

Musk thistle
       Canada thistle (Kirk Henderson)            Musk thistle (Plant Conserv. Alliance)    

All landowners are required to control those weeds on their property that have been declared noxious by the State of Iowa or by Dallas County.   Noxious weeds growing within city limits, in abandoned cemeteries, along railroads, streets, and highways, as well as on farmland, or any private or public land, must be controlled. The Dallas County Weed Commissioner enforces the Iowa Noxious Weed Law and the County's Noxious Weed Control Program. 


How Do I Contact the County Weed Commissioner?

Every county in Iowa has a weed commissioner to oversee that County’s noxious weed control program. The Dallas County Weed Commissioner is located at the Secondary Road Dept., 415 River St., Adel, IA 50003. Phone (515) 993-4289.  If you wish to file a weed complaint, weed complaints will be handled as follows:

"The complaint will not have to be signed and may be phoned in at the number above.  State the weed species in question, the legal description of the property, the location of the weeds on the property, the owners of the land, and the tenants or persons in control of the land.  Forms are available at the Weed Commissioner’s office and will be mailed on request."

Iowa's noxious weed law also prohibits the sale and distribution of purple loosestrife (Lythrum salicaria).  This weed is also prohibited by Iowa's Aquatic Invasive Species Law along with European wand loosestrife (Lythrum virgatum). 

Purple loosestrife

Below is a list of additional plant species which are considered invasive or aggressive by the Dallas County IRVM Program and County Weed Commissioner. These species are unsuitable for use or growth in roadside plant communities. Because of concern for their spread into public right of ways, planting these species in adjacent private lands is discouraged. This plant species list is not all-inclusive, and may be edited to include or remove certain species as conditions or situations dictate.

  • Japanese Knotweed (Polygonum cuspidatum)
  • Pampas Grass (Miscanthus spp.)
  • Garlic Mustard (Allaria petiolata)
  • Crown Vetch (Coronilla varia)
  • Wild Parsnip (Pastinaca sativa)

Species that are not declared noxious but are declared nuisance weeds by the Dallas County IRVM program for various reasons include:

  • Marijuana (Cannibas sativa)
  • Giant Ragweed (Ambrosia trifida)

What Can I Do to Help?

Don’t Plant Invasive Weeds. Be selective when you choose plants for home landscaping. Some invasive plants, such as purple loosestrife varieties, are still illegally sold in nurseries and garden shops, so beware! If you plant these in your yard, they may escape into nearby areas and become a problem by displacing native species. Not all non-native plants are invasive. There are many beautiful horticultural plants available for you to choose from, without contributing to the invasive weed problem. Also consider planting native species in your home garden. Natives offer a good choice for home landscaping because they are well adapted to local conditions and often thrive with less care than required by many non-native plants. Native plant gardening also enhances the value of your yard for local wildlife including birds and butterflies.

Remove Invasive Weeds. Be on the lookout for invasive weeds and remove or report them whenever possible. You may have invasive plants already growing in your backyard. Birds and other animals may eat the seeds of these plants and then travel to nearby uninfested lands, resulting in the spread of invasive weeds. You can help stop these invasions by removing the source plants. Talk to your neighbors and local greenhouses about the problem and share your concerns. Report sightings on public lands to the land manager. And if you do remove these plants from your own land, be sure not to spread the seeds when disposing of them.

Help Prevent the Accidental Spread of Invasive Weeds. When you venture into natural areas, roadsides, or any place with invasive weeds, be aware that you could be introducing or carrying invasive weeds inadvertently. Check your shoes, socks, clothing, etc., which might carry seeds. Another important thing you can do is to try to limit soil disturbances on your property. Invasive weeds thrive on disturbance and can quickly colonize areas that don’t have a good vegetative cover. If invasive weeds are moving in, try to control them before they get well established and the area is infested.

Educate Yourself And Spread The Word. Become better informed about how to identify invasive weeds, how to avoid spreading them, and how to control them. The battle to control invasive weeds cannot be won without public awareness and support.  Share what you have learned so that others can join in the WAR ON WEEDS!

Here are some groups and agencies that can provide further information or assistance on noxious weeds:

  • Dallas County Extension Service (515) 993-4281
  • Iowa Department of Agriculture & Land Stewardship (515) 281-5321
  • Dallas County Natural Resource Conservation Service office (515) 993-3413
  • Iowa Department of Transportation (515) 233-7729
  • Iowa State University (Agronomy) (515) 294-1923
  • The Nature Conservancy (515) 244-5044

Related Websites:

Material for this website was adapted from: Johnson County's Secondary Roads / Noxious Weeds pages with permission from the Johnson County IRVM program of Johnson County, Iowa.