Quick guide: How to identify and control spring dead spot and large patch
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August 12, 2024
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By Lane Tredway, Ph.D., technical services manager for Syngenta
When it comes to warm-season grasses, fall fungicide applications that protect against large patch and spring dead spot are crucial for maintaining spring quality.
Identifying spring dead spot
Spring dead spot often goes unrecognized or misdiagnosed in lawns and landscapes.
- Bermudagrasses are most susceptible, but zoysiagrasses can also be affected
- Root infection begins in the fall when soil temperatures decline below 80 F.
- Symptoms appear in spring when turf comes out of dormancy
- Circular patches up to several feet in diameter appear to remain dormant, but are actually dead
- Recovery is very slow and can take the entire growing season in severe cases
- Sign up for Spring Dead Spot alerts
Recognizing large patch
- Zoysiagrasses, centipedegrass and St. Augustinegrass are most susceptible. Bermudagrass can also be affected.
- The disease develops in fall and spring when soil temperatures are below 70 F
- It is particularly aggressive during extended wet weather
- Large patch attacks when warm-season grasses are growing slowly and preparing for dormancy
- Symptoms can linger until spring when growth resumes
- Look for circular patches of blighted turf up to several feet in diameter
- Multiple patches can coalesce to kill large irregular areas
- Outer edges may have a bright red, orange or yellow coloration in active infestations
- Sign up for Large Patch alerts
Prevent spring dead spot and large patch with Compendium fungicide
Compendium® fungicide was developed specifically for lawn care operators and combines two active ingredients, azoxystrobin and propiconazole that work together to help protect turfgrasses from large patch, spring dead spot and more.
Application timing and rates
For best control of spring dead spot and large patch:
- Make two fall applications of Compendium at 2.6 fl. oz./1,000 ft.2
- First application when soil temperatures dip below 70 F (mid-September to mid-October in the transition zone)
- Make the second application 28 days later
- Water-in with at least 1/8” of irrigation as soon as possible after application
- One spring application should be made when soil temperatures consistently rise above 60 F. This application does not need to be watered in.
- Where spray applications or irrigation is not feasible, Headway® G fungicide is a very effective option at 3.5 to 4 lbs./1,000 ft.2 at the same timings
- For more precise timing monitoring soil temperatures in your area, sign up for automated soil temperature alerts
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.
© 2024 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.