Brown Lawn Overnight? It Might Be Ascochyta Leaf Blight
- Danny at Spring Touch
- Jun 24
- 2 min read
Brown Lawn Overnight? It Might Be Ascochyta Leaf Blight
Ever wake up to find big, brown patches that weren’t there yesterday? Your lawn may be dealing with a fast-acting summer fungus called Ascochyta Leaf Blight. It’s a mouthful—but it’s more common than you’d think, especially here in Minnesota.
The good news? While it looks dramatic, Ascochyta usually doesn't do permanent damage. Your lawn can recover—with a little patience and some TLC.
What Does Ascochyta Leaf Blight Look Like?
This fungus doesn’t waste time. It shows up quickly—sometimes overnight—as:
Large, irregular straw-brown patches
Grass that appears dry or scorched
Blades that die back from the tip, but not the root
You’ll often see it right after a period of rain followed by heat—prime conditions for a fungal flare-up.
Check out this helpful info from Iowa State University:
Why It Happens
Ascochyta loves:
High heat and humidity
Sudden weather changes (sound familiar?)
Lawns with thick thatch or poor drainage
Short mowing during stress periods
It also tends to strike when the grass is already weakened—usually from dull mower blades, poor watering habits, or compacted soil.
How to Handle It
Step 1: Don’t panic
Even though your lawn may look dead, Ascochyta usually doesn’t harm the crowns or roots—so most of the grass will bounce back within 2–3 weeks.
Step 2: Rake gently
Once the grass is dry, use a leaf rake to lift and fluff matted areas. This helps the lawn breathe and recover faster.
Step 3: Adjust your lawn care routine
Mow at the right height (2.5–3 inches)
Avoid mowing when grass is wet
Aerate yearly to reduce thatch and improve drainage
Water deeply and early in the day so grass can dry before nightfall
Step 4: Still not sure? Send us a photo
If you’re unsure whether it’s Ascochyta or something else, just text (507) 934-5296 or email us a photo at info@springtouchlawn.com. We’ll take a look and help you diagnose the issue.
Recurring Problem? We Can Help
If Ascochyta keeps coming back year after year, it may be time for a more targeted approach. Spring Touch offers fungus control treatments to help reduce outbreaks and support a stronger, more resilient lawn.
