NOTE: Tenacity is a herbicide that is now labeled for buffalograss.  It was not labeled when this video was made.  Tenacity is selective and will not harm the buffalograss but will control windmill grass though it may take two applications.  However, Tenacity is not marketed for homeowners but can be purchased through certain online distributors.  It is not restricted use.
One of the potential drawbacks with buffalograss is that it doesn't grow quite as dense as other turfgrasses. That leads to more opportunities for weed seeds to germinate in the buffalograss stand and contaminate the lawn with weeds. This segment shows how to control one of those weeds -- windmill grass.

Produced by the Department of Communications at Kansas State University. For more information, visit our website at:

Buffalograss - Controlling Windmill Grass

One of the potential drawbacks with buffalograss is that it doesn’t grow quite as dense as other turfgrasses such as tall fescue, Kentucky bluegrass, zoysia grass or Bermuda grass. Therefore, the plants aren’t as close together as the other grasses. And, that leads to more opportunities for weed seeds to germinate in the buffalo grass stand and contaminate the buffalo grass stand with weeds.

Some common examples of weed problems in buffalograss are tall fescue, Kentucky bluegrass, Bermuda grass, and henbit is a big problem in the spring. What we’re looking at here today is windmill grass.

Windmill is a perennial grassy weed. Once the plant has germinated, it will live here forever until we do something about it. Some of the key identifying characteristics of windmill grass is the seed head. The seed head will germinate and will have a windmill or bicycle wheel shape. The seeds expand into all different directions.

Windmill grass is a warm season perennial grass. It greens up in the springtime at the same time as buffalograss. It grows well during the summer, and then it turns brown and goes dormant in the fall like buffalograss. Therefore, it makes it harder to find selective herbicides that can remove windmill grass from a buffalograss stand. Currently, homeowners can remove windmill grass from a buffalograss stand by spraying with a non-selective herbicide such as Roundup or herbicides that contain the active ingredient glyphosate.

Typically, you’ll want to make sure that you apply the herbicide when the weed is actively growing. Many people may want to apply the herbicide when they see patches of the weed in the early spring. However, the windmill grass isn’t growing in the early springtime, so it’s best to control this weed when it’s actively growing in June and July.

This feature story prepared with Rodney St. John, former Turf Specialist with Kansas State University Research and Extension. For more information, visit your local county extension office or visit our website at

Horticulture Newsletter

KSU Horticulture Newsletter

Get more information from our weekly newsletter.

Find Your Local Office

Have questions or need help?

Local Extension Office Map

Click the map to find your Local Extension Office.

YouTube Videos

YouTube Videos

Watch K-State Research and Extension Videos.

Kansas Healthy Yards Tagline