Ready to put your weed identification skills up against the best? Join us for the annual Iowa State Fair Weed Identification Contest on Friday, August 14 in front of the Agriculture Building. 

Contest Details

This contest takes place from 9 - 11:30 a.m. on the first Friday of the Iowa State Fair (Aug. 14, 2026) and contestants are welcome to participate anytime during that window. This contest has three divisions so participants of all ages are welcome: youth (under 19), adult-general, adult-professional. Future agronomists (youth) will identify 20 common Iowa weeds; those in the general division will identify 30 weeds; and professionals will identify all 30, as well as five extra-challenging Iowa weeds.

Following the contest, winners from each division will be announced during the awards ceremony, held inside the Agriculture Building at 3 p.m. on Aug. 14. The top five winners in each division will receive a cash prize and a coveted Iowa State Fair ribbon. 

Weeds from the contest — including their common names and interesting facts — will remain on display for the duration of the fair in the lower level of the Agriculture Building.

Weed Identification Resources

Want to prepare for the contest? Review the following weed identification resources:

• Weed Identification Field Guide – 2nd Edition
• Iowa State University Weed Identification Fact Sheets
• University of Missouri Weed ID Guide
• Weed identification apps (Examples: iNaturalist, PictureThis, PlantNet)