By Travis Roberson, Ph.D., technical services field manager for Syngenta Digital Platforms

Anthracnose | Fairy Ring | Summer Patch 

The 2026 winter season was one filled with many challenges for turfgrass managers across the country. Winter Storm Fern brought devastating ice, snow and record cold from the Gulf Coast to the Northeast, while a late-season blizzard in March dumped historic snowfall across the Midwest and Great Lakes. All followed by an unusual warm spell that began decimating turf out of dormancy. The prolonged snow cover, ice encasement and early spring conditions that defined this winter have left many stands of turf – particularly Poa annua and warm-season grasses in the Transition Zone – weakened, stressed and slow to recover. As grass now emerges from dormancy in a compromised state, that weakened root system and depleted energy reserves make it significantly more susceptible to the disease pressures that typically accompany spring. Turf that may struggle from winterkill and crown damage this season has far less capacity to fight off infection, creating ideal conditions for anthracnose, fairy ring, summer patch and other spring diseases to take hold earlier and with greater severity than in a typical year. Proactive spring disease management has never been more important.

Maximizing control of these diseases begins by equipping yourself with the most accurate knowledge of proper chemistry and optimal application times. GreenCast^® Connect, a mobile app from Syngenta, can help you optimize your application timing by pairing site-specific weather data with predictive modelling to alert you when action is needed. The weather data driving the alerts captures information based on the location the user establishes and geolocates to within two square miles for a high-level of precision.

Anthracnose

Conditions favoring anthracnose development range from cool and wet to hot and dry. The disease is more prevalent when turfgrass is stressed because of cultural practices, drought, soil compaction, poor water drainage and/or low fertility inputs. When conditions are favorable for disease development, consider applying Ascernity^® fungicide (1 fl. oz./1,000 ft.²), Daconil^® Action™ fungicide (3.5 fl. oz./1,000 ft.²) and Velista^® fungicide (0.5 oz./1,000 ft.²). To see all leading solutions for anthracnose control, view the fungicide efficacy chart here and learn more about tips for anthracnose control on Poa annua greens here. 

GreenCast Connect links data to disease development, helping users confidently choose the best timing for product applications. Visual alerts are displayed as a concise view of current conditions on the dashboard (Figure 1A) and a more detailed view with a seven-day historical, current and fourteen-day forecast of the disease outlook (Figure 1B).

Fairy ring 

Fairy ring, a common turfgrass disease, has three types, with Type 1 being the most difficult to manage. Type 1 causes hydrophobic soils that repel water in actively growing areas, leading to drought stress later in the season. Monitoring for preventive applications begins in the spring when soil temperatures remain >55°F, and treatment is recommended when soil temperatures are sustained >60°F. Rotating Briskway^® (0.7 fl. oz./1,000 ft.²), Velista (0.7 fl. oz./1,000 ft.²) and Posterity^® XT  fungicides (3 fl. oz./1,000 ft.²) is recommended, depending on whether you manage ultradwarf bermudagrass or creeping bentgrass putting greens. 

Greencast Connect users can take advantage of their properties’ modeled soil temperature data to track disease development of soilborne diseases such as fairy ring. The dashboard can be customized for visuals of soil temperature and specific diseases in a concise view of current conditions on the dashboard (Figure 2A) and a more detailed soil temperature view with a seven-day historical, current and fourteen-day forecast (Figure 2B). Greencast Connect also displays the average soil temperature on a three-, seven- and 14-day historical and forecasted outlook to provide simple trends of what has happened and what is to come so users can plan targeted maintenance applications.

Summer patch

Summer patch affects several cool-season grass species, especially Kentucky bluegrass, as well as mixed stands of annual bluegrass and creeping bentgrass putting greens. On putting greens with mixed cool-season turf the disease becomes difficult to control once symptoms appear. Symptoms of infection include thinned or wilted turfgrass with white, bleached leaves coalescing into larger yellow patches of affected areas from 3-18 in. in diameter. These patches do not become apparent until stressed conditions of >85°F occur, but the root infection by the fungus occurs much earlier in the season when soil temperatures begin to exceed 65°F at a 2-in. soil depth for three consecutive days. This fungal colonization in the roots compromises and weakens the desired turfgrass species. 

Timing applications for disease management is crucial. Consider fungicides like Headway^® (1.5-3 fl. oz./1,000 ft.²),  Posterity XT (1.5-3 fl. oz./1,000 ft.²) and Velista (0.5-0.7 oz./1,000 ft.²). Visit the online disease ID guide and fungicide efficacy chart on GreenCastOnline.com for additional control options. 

For a more compact overview of pests related to your organization, GreenCast Connect features a customized Pest Risk Monitor overview (Figure 3A) within the dashboard. This allows users to get a snapshot of their current conditions and a three-day forecast of what actions to expect. 

For even more precision, users with Spiio™ soil sensors can customize thresholds related to site-specific, in-ground soil data and receive alerts driven by desired soil moisture, temperature or salinity thresholds (Figure 3B). Capturing this level of insight that is backed by data from your property allows you to maximize treatment efficacy for these diseases and many others featured in the GreenCast Connect app. 

Learn more about GreenCast Connect or download the app at GreenCastConnect.com. 

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

© 2026 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. Action™, Ascernity^®, Briskway^®, Daconil^®, GreenCast^®, Headway^®, Posterity^®, Velista^® and the Syngenta logo are trademarks of a Syngenta Group Company. Spiio™ is a trademark of Spiio, Inc. All other trademarks are the property of their respective third-party owners.