By Lisa Beirn, Ph.D, technical services manager, Syngenta

Tenacity^® herbicide is a systemic herbicide for pre- and post-emergent control of grass and broadleaf weeds in several cool- and warm-season turf species. The active ingredient, mesotrione, is based on a naturally occurring compound produced by the bottlebrush plant (Callistemon citrinus). Tenacity works by inhibiting the synthesis of carotenoids in susceptible plant species. Without carotenoids, light energy and by-products of photosynthesis destroy chlorophyll and cell membranes, resulting in bleaching of leaves and plant death.

Tenacity, available in a convenient squeeze-and-pour bottle, provides control of major turf weeds including:

• Crabgrass 

• Goosegrass 

• Lovegrass 

• Chickweed 

• Dandelion 

• Oxalis 

• Speedwell 

• Canada thistle 

• And many others (see product label) 
  
  

See what others in the industry have to say about Tenacity: Watch these videos to learn more.

Product use rates range from 5-8 oz./A. A repeat application in two to three weeks may be necessary for weed control. Tenacity also controls bentgrass and nimblewill contaminations in Kentucky bluegrass and perennial ryegrass turf, and it is compatible with a seeding program into treated areas to enhance conversion.

Tenacity offers several unique features including, including the ability to: 

• Synergize weed control when tank mixed with other active ingredients

• Provide clean up for summer annuals and perennial weeds such as crabgrass, clover, dandelion and oxalis in late spring and early summer 

• Tank mix with a post-emergent herbicide, such as triclopyr (TE) or dicamba, to enhance post-emergent control of crabgrass and dicot weeds (see chart below) 

Trial source: North Carolina, 2008


Tenacity can also be used at seeding to reduce weed competition and establish a lawn faster. When applied just prior to or at seeding of tall fescue, Kentucky bluegrass and perennial ryegrass, Tenacity will help control crabgrass, purslane and carpetweed (among other weeds) that seem to germinate at turf renovation. Tenacity can also be added to the hydro-seeding tank for seeding large areas.

A new seeding of a Kentucky bluegrass and perennial ryegrass blend, 2007.

The Silver Cymbal and Pest and Lawn Ginja video content referenced are compensated endorsements.

For more information about Tenacity, visit GreenCastOnline.com/Tenacity or contact your local Syngenta territory manager.

Performance assessments are based upon results or analysis of public information, field observations and/or internal Syngenta evaluations. Trials reflect treatment rates commonly recommended in the marketplace.

All photos and videos are either the property of Syngenta or are used with permission.

© 2023 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration and proper use. GreenCast^®, Tenacity^® and the Syngenta logo are trademarks of a Syngenta Group Company. All other trademarks are the property of their respective third-party owners.