Blog Post August 6th, 2025

Why Lawn Fungus Has Been So Common in 2025 — A Midwestern Perspective

If your lawn in the Chicago suburbs is struggling with brown patches, thinning spots, or strange growth patterns this summer—you're not alone. At Fresh Cut Pros, we've seen a noticeable uptick in lawn fungus issues across Shorewood, Joliet, Plainfield, Minooka, and Channahon. Here’s what’s going on.

The Perfect Storm for Lawn Fungus

Lawn fungus loves two things: moisture and humidity—and 2025 has delivered both in abundance.

This spring and early summer, much of the Midwest experienced above-average rainfall combined with higher-than-usual overnight humidity levels. According to Purdue Extension and the University of Illinois, this creates ideal conditions for common turf fungi like:

Brown Patch (Rhizoctonia solani)
Dollar Spot
Leaf Spot
Red Thread

These diseases typically affect cool-season grasses like Kentucky Bluegrass and Perennial Rye, which are common in Illinois lawns. Brown Patch, for example, thrives when nighttime temps stay above 68°F and lawns remain wet for extended periods—conditions we've had for weeks.

But Isn’t It Usually Hotter?

You’re not wrong to ask. Many of us associate fungus with hot, steamy weather, but that’s only part of the story. One of the reasons this year has been particularly tricky is the cooler-than-average winter we had. Less snow cover and milder soil temperatures meant pathogens survived more easily, making spring fungus flare-ups more common and severe.

Why It Matters

Fungal infections weaken your lawn’s natural defenses, opening the door for further stressors like weeds, insect damage, and drought stress. Left untreated, they can result in long-term thinning or even complete turf loss.

What You Can Do

Mow high: Keep your grass at 3.5" to 4". This helps shade the soil and encourages deeper roots.
Water smart: Water deeply and early in the morning. Avoid watering at night.
Bag when needed: If you’re seeing signs of active fungus (brown rings, gray webbing), consider bagging clippings temporarily to reduce the spread.
Stay on your fertilization plan: A well-fed lawn is more resilient. We customize our fertilization and weed control to adapt to the season’s pressures.
Ask about fungicide: In rare cases, fungicide applications may be necessary—but we only recommend them when absolutely needed.

Why Preventative Fungicide Isn't Part of Standard Packages

Until recently, fungal disease wasn't a significant problem here, so our standard lawn care packages didn’t include fungicide. As the risks have risen, we've developed a targeted preventative and curative program that we now offer specifically when a lawn shows signs of fungus or has a history of the issue. Not all clients need it—but for those experiencing disease, we now provide a plan to prevent and control outbreaks effectively.

✅ What We're Doing Now

We now track disease trends and adapt treatment plans proactively as seasons change.
Our preventative program includes applications timed in spring and early summer, rotating fungicides to avoid resistance.
We follow cultural best practices, including watering advice, mowing height guidelines, and aeration.

Final Thought

This season’s conditions are challenging, but not unmanageable. Our six-round lawn care program is designed to support healthy turf year-round, and when fungus flares up, we’re ready with treatment options and advice.

Sources:

Horst, R. K. Compendium of Turfgrass Diseases. APS Press, 2013.
Purdue University Extension. “Turfgrass Disease Management.” www.turf.purdue.edu.
University of Illinois Extension. “Common Turfgrass Diseases in Illinois.” web.extension.illinois.edu.
National Weather Service. “Midwest Regional Climate Summary – Spring 2025.” www.weather.gov.
Weather and Climate Info. “Illinois Rainfall Trends 2025.” www.weatherandclimate.info.