How to identify and control spring dead spot

By Lane Tredway, Ph.D., technical services manager for Syngenta

When it comes to warm-season grasses, spring quality is influenced more by what you do (or don’t do) the previous fall. Sending the turf into winter dormancy in a strong, healthy condition determines how well it survives the winter and greens up in the spring. Fall fungicide applications that protect against large patch and spring dead spot are an important part of this equation.

Identifying spring dead spot

Spring dead spot often goes unrecognized or misdiagnosed in lawns and landscapes. Bermudagrasses are most susceptible to it, but zoysiagrasses can be affected as well. Spring dead spot symptoms appear in the spring when the turf comes out of winter dormancy. Circular spots and patches up to several feet in diameter appear to remain dormant, but are actually completely dead. Recovery from spring dead spot is very slow and, in severe cases, it can take the entire growing season.​​

Slow spring dead spot recovery on Tifway bermudagrass in Raleigh, North Carolina. Source: Lane Tredway, Syngenta, 2005.

Recognizing large patch 

Large patch is another severe disease of warm-season grasses, with zoysiagrasses, centipedegrass and St. Augustinegrass being most susceptible. The disease develops in fall and spring when soil temperatures are below 70 F, and is particularly aggressive during extended periods of wet weather. Symptoms typically appear as circular patches of blighted turf up to several feet in diameter, but multiple patches can coalesce to kill large irregular areas. When large patch is actively developing, outer edges of the patches often have a bright red, orange or yellow coloration.

Large patch. Source: Syngenta, 2003

Introducing Compendium fungicide

Compendium™ fungicide is a new formulation with a combination of two active ingredients, azoxystrobin and propiconazole, developed specifically for lawn care operators (LCOs). These active ingredients work together to provide outstanding control of both spring dead spot and large patch, along with other common diseases like leaf spot, dollar spot and rust. Compendium is available in a compatible and easy-to-mix soluble concentrate (SC) formulation to deliver the power and flexibility LCOs demand.

For best control of both spring dead spot and large patch, make two applications of Compendium at 2.6 fl. oz./1000 ft.2 on a 28-day interval:

  • The first application should be made when soil temperatures dip below 70 F, which is typically between mid-September to mid-October in the transition zone.
    • Sprays targeting spring dead spot should be watered-in with at least 1/8 in. of irrigation as soon as possible after the application is made.
  • An additional application should be made in the spring for large patch control when soil temperatures consistently rise above 60 F. For more precise timing, you can monitor soil temperatures in your area by signing up for automated soil temperature alerts.

​​​​​​​Where spray applications are not possible or irrigation is unavailable, a granular formulation like Headway® G fungicide is a very effective option for spring dead spot and large patch control. Headway G should be applied at 3.5 to 4 lb./1000 ft.2 at the same timings discussed above for best results.

For more information about spring dead spot control in lawns and landscapes, contact your local Syngenta territory manager.

*Always consult the product label for complete use and application information.

All photos 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. Compendium™, Headway® and the Syngenta logo are trademarks of a Syngenta Group Company.

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