Summer patch hits hard in early August; fall rust outbreaks causing orange shoes; cool temperatures allowing a head start on recovery plans.
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- Figure 1. A: August, while still warm, has turned joyfully mild (MRCC). B. ‘False fall’ is really convincing and forecast to last into early September (NOAA).
August in the region started cool, got back to summer hot, and now dare I say it feels like fall. This “false fall” in Indiana certainly is convincing as a stagnant high-pressure dome descended from Canada last week. Today was the coldest August 26 in the last 43 years with lows in the 40s across upper and middle Indiana. Recent temperatures have been 10- 12 degrees below normal and brought monthly average temperatures back to near average after a solid span of heat with 90F + highs from August 8 – 19. The total number of days >= 90 F in Indy is 29 days, 5th most in the last 15 years (2018 – 38 and the brutal three year stretch from 2010 – 37, 2011 – 42, and 2012 – 51 days). With the prescribed forecast indicating no major shifts, perhaps the summer spikes are finished and the time is nigh to get into recovery mode.
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- Figure 2. Summer patch on bluegrass and bentgrass. A. Summer patch + heat stress on bentgrass green. Inset- ETRI in roots. B. Summer patch symptoms on Kentucky bluegrass rough. Inset- Individual plant symptom.
Summer patch arrived with numerous samples to the diagnostic lab starting in early August. Kentucky bluegrass on lawns and golf course roughs was severely affected as were numerous bentgrass putting greens broadly throughout the region. These summer patch infections of roots, stolons and rhizomes likely started occurring and accruing much earlier in the summer. Some of the samples displayed dark necrosis up into the leaf sheath and crown tissue.
To read the rest of the Purdue Turfgrass Disease Report, click here: https://mrtf.org/wp-content/uploads/2025/08/Purdue-Turfgrass-Disease-Report_082625.pdf
To become a member of the Midwest Regional Turfgrass Foundation, click here: www.https://mrtf.org/
