Extension specialist urges caution when making herbicide selection

“Traditional” Roundup Weed and Grass Killer (shown left) contains the active ingredient glyphosate, a nonselective herbicide that kills most plants. The new Roundup for Lawns (right) contains the active ingredients MPCA, quinclorac, dicamba and sulfentrazone to kill weeds but not the lawn. (Cheryl Alberts, Pesticide Safety Education Program)

May 5, 2017

Lincoln, Neb. —New in 2017 is a lawn product name that may sound familiar. But the new Roundup for Lawns is a stark contrast from the traditional Roundup herbicide, said a Nebraska Extension integrated turfgrass management specialist.

“The two products have completely different ingredients and are not interchangeable,” said Cole Thompson, who is based at the University of Nebraska-Lincoln.

Thompson said in addition to the Roundup name similarity are other consumer-awareness factors:

  • Multiple Roundup products may be displayed together in stores, so consumers must know what they are purchasing.
  • Pricing between the two Roundup products may differ – do not automatically select the least expensive, which likely is the “traditional” Roundup.

Consumers in-store or online must carefully read product labels to correctly determine the active ingredients are what they intend to purchase and use, Thompson said.

Roundup Weed and Grass Killer is a brand name of an herbicide that contains glyphosate. This active ingredient nonselectively kills most plants, including both broadleaf and grasses, Thompson explained. Homeowners often use this product to kill anything growing in cracks, between patio pavers, even entire lawns, for example. Agricultural producers also use  glyphosate in their fields to kill unwanted plants.

“Though there are always exceptions, consumers should expect that all plants sprayed with Roundup Weed and Grass Killer will die,” Thompson said.

Roundup for Lawns on the other hand, is the brand name of a new herbicide that does not contain glyphosate; rather it contains the active ingredients MCPA, quinclorac, dicamba and sulfentrazone. Each is a selective herbicide that controls various weeds without harming Kentucky bluegrass, perennial ryegrass or tall fescue lawns.

“Research trials do, however, show that some active ingredients in Roundup for Lawns (MPCA and dicamba) could cause short-lived injury to buffalograss lawns,” Thompson said.

In addition to reading the label for the active ingredients, consumers must follow safety directions. When handling and applying pesticides, at minimum wear a long-sleeved shirt, long pants, shoes, socks and chemical-resistant gloves.

Other manufacturers have products that contain similar ingredients as Roundup for Lawns and target the same weeds, Thompson said, adding labels will list product ingredients.

Other Roundup products are also available for home use. Roundup for Lawns for use on Southern Grasses contains an active ingredient that may injure cool-season lawns. Roundup Extended Control and Roundup Max Control 365 both contain imazapic, a soil residual herbicide that kills germinating cool-season grass seedlings for weeks after application. Thompson advised avoiding using these extended control products in renovations where seeding will take place soon after application.

For more articles on lawn and turf care see http://turf.unl.edu/turf-info.

Cole Thompson
Integrated Turf Management Specialist

Writer: Cheryl Alberts - Pesticide Safety Education Program