08/17/2026
Mid-August to mid-September is the best time to establish a new lawn or renovate a thin lawn.
This is because the cool-season grasses typically used in Iowa will germinate quickly in the warm soil of late summer, and the warm fall days and cool nights promote rapid turf growth. Also, fewer w**d species germinate in the fall, so there is little w**d competition.
Use the following resources based on whether you're seeding a new lawn or renovating your current one:
Seeding New Lawn: https://go.iastate.edu/TYLEQ7
Renovating Lawn: https://go.iastate.edu/4JBPPN
Iowa State University Extension and Outreach ISU Extension and Outreach - Agriculture and Natural Resources Iowa Master Gardeners