Early Signs of Brown Patch in Houston Lawns and What to Do About It
TL;DR Summary:
Brown patch fungus shows up in Houston lawns when overnight temperatures dip into the 60s and mornings stay damp. The first signs are yellow circles or patches with bright yellow edges. Once you see those, it’s time to treat immediately with Heritage G fungicide to stop it from spreading. Even better, apply Heritage G preventatively in late September to protect your lawn before brown patch takes hold.
Brown Patch FAQ — Houston Lawns
If you’ve spotted yellow circles or thinning patches in your lawn this fall, you’re not alone. Every year around late September, we start getting calls about brown patch showing up across the Houston area. Below are some of the most common questions we hear from homeowners about what causes brown patch, how to identify it early, and the best ways to treat and prevent it — especially for St. Augustine and Zoysia lawns here in Southeast Texas.
Early Fall Means Brown Patch Season in Houston
Hi, I’m Michael Romine with Houston Grass, and at the very end of September—when mornings start feeling cooler and dew lingers on the lawn—it’s the start of brown patch season in our area. This common lawn fungus thrives in the mild, wet conditions we typically see this time of year.
If you have St. Augustine grass, this is the time to start watching closely for the first signs of infection.
How to Recognize the Early Signs of Brown Patch
Even in a healthy lawn, brown patch can appear quickly once the conditions are right. Here’s what to look for:
1. Circular Yellowing
The first clue is often a circle of yellow grass. The center may still look healthy, but the edges of the patch turn bright yellow—that’s the telltale early sign.
2. Random Placement
Brown patch doesn’t just occur in low spots or areas with standing water. It can start anywhere, even on a sloped, well-drained part of your yard.
3. Wet Morning Conditions
If your grass stays wet after watering or morning dew—and temperatures are around 65°F or below at sunrise—you’re in prime brown patch territory.
Why Brown Patch Appears in the Fall
The fungus that causes brown patch (Rhizoctonia solani) becomes active when:
- Night temperatures fall into the 60s
- Daytime highs are still in the 80s
- Humidity stays high and lawns stay moist
These conditions typically hit late September through November in the Houston area, making it the perfect storm for this disease.
How to Stop Brown Patch Before It Spreads
Apply Heritage G Fungicide
If you’re starting to see yellow patches or circles, it’s time to apply Heritage G. It’s one of the most effective products for both preventing and controlling brown patch fungus.
- For prevention: Apply Heritage G in late September or early October before symptoms appear.
- For treatment: Apply as soon as you notice yellow circles or patches—it can stop the fungus in its tracks.
Avoid Overwatering
Continue watering your lawn as needed, but avoid keeping it too wet. Early morning watering is best so the grass dries during the day.
Final Thoughts from Michael
As Michael explains in the video, even a well-maintained yard can develop brown patch when the weather turns cool and damp. The key is catching it early and treating it right away.
“Brown patch season is upon us,” Michael says. “Get you some Heritage and get it out there. If you already have it, it’ll stop it in its tracks—and if you don’t, it’ll keep it from showing up.”
Recommended Products
✅ Heritage G Fungicide — Prevents and treats brown patch fungus
✅ Nitro-Phos Fall Special Fertilizer — Supports healthy fall growth
✅ Barricade Pre-Emergent Herbicide — Stops winter weeds before they start
All available at Houston Grass in Arcola, TX — where our family has been growing top-quality sod since 1981.
