Necrotic Ring Spot: A Tough Lawn Fungus That Might Be Hiding in Plain Sight
- Danny at Spring Touch
- Jun 24
- 2 min read
If your lawn has light brown, straw-colored circles that never seem to bounce back—especially in the same areas year after year—you might be dealing with Necrotic Ring Spot.
It’s a frustrating fungus that often shows up in newer lawns, especially those with compacted soil or poor drainage. The tricky part? It can look a lot like other lawn diseases, but unlike some, Necrotic Ring Spot attacks below the surface—damaging the roots of your grass.
What Does Necrotic Ring Spot Look Like?
This lawn fungus creates:
Circular patches of straw-colored or dead-looking grass
Spots usually less than 12 inches wide
A “frog-eye” pattern—where the center recovers slightly, surrounded by a ring of damaged grass
It tends to show up in the summer, especially after periods of cool, wet weather followed by heat and drought.
Want to compare what you’re seeing? The Michigan State University and Purdue have great info and photos:
Why Does It Happen?
Necrotic Ring Spot thrives in:
Compacted soil with poor drainage
Lawns that haven’t been aerated
Areas with heavy thatch buildup
Newer sod installations, though seeded lawns aren’t immune either
The fungus weakens or kills the roots, which is why the grass doesn’t recover like it would with some surface-level diseases.
How to Fight Back
Step 1: Aerate
Liquid aeration helps reduce compaction, improve drainage, and give roots room to grow. It’s one of the best things you can do to help your lawn recover—and keep this fungus from coming back.
Step 2: Fertilize consistently
Keeping your lawn well-fed throughout the growing season gives it the strength to resist stress and recover more quickly.
Step 3: Avoid shallow watering and short mowing
Water deeply, not often—and never mow too short. The added stress can make your lawn more vulnerable to disease.
Not Sure If It’s Necrotic Ring Spot? We Can Help.
This one can be tricky to diagnose. If you’re not sure what you’re seeing, text (507) 934-5296 or email us a photo at info@springtouchlawn.com and we’ll help you figure it out.
And if Necrotic Ring Spot keeps popping up in the same areas every year, it may be time to get proactive. Spring Touch offers fungus control treatments to help break the cycle and get your lawn back on track.
