Houston Fall Lawn Prep: Fertilizer, Pre-Emergent & Brown Patch Prevention
Quick answer: To prepare a Houston lawn for fall, do three things between late September and November. Feed it with a low-nitrogen fall fertilizer such as Nitro-Phos Fall Special (8-12-16). Apply a pre-emergent such as Nitro-Phos Barricade to stop winter weeds. Treat for brown patch with a fungicide such as Heritage G before cooler nights arrive.
In this late September update, Michael Romine of Houston Grass explains each step from our sod yard. He also shares why fall is the wrong time to try to green up your lawn.
Why fall lawn care matters in Houston
Fall care decides how your lawn looks next spring. Even when it’s still 95 degrees in late September, cooler nights are close. Your St. Augustine, Zoysia or Bermuda grass is starting to prepare for winter dormancy.
The goal now is to strengthen the roots and stems, not to push new top growth. Texas A&M AgriLife Extension recommends making the last nitrogen application 4 to 6 weeks before your area’s first frost. Too much fall nitrogen can increase winter kill and disease (AgriLife Extension). In the Houston area, the first real frost usually arrives in mid to late December.
Step 1: Use a low-nitrogen fall fertilizer
Apply a fall fertilizer with a low first number in October and November. At Houston Grass, we carry Nitro-Phos Fall Special, an 8-12-16 blend.
The three numbers on a fertilizer bag show nitrogen, phosphorus and potassium, in that order. Nitrogen is what greens up a lawn. Spring and summer blends have a much higher first number than Fall Special’s 8.
Many customers call this time of year asking how to green up their yard. Michael’s answer: fall is not the time to green up your lawn. Instead, you’re feeding the roots and stems so the grass goes into dormancy healthy and comes out strong in spring.
If you use a different product, avoid fertilizers with a first number above about 15. Extra nitrogen in fall produces lush growth, and the brown patch fungus readily attacks that kind of growth (Texas A&M AgriLife, Bexar County).
Step 2: Apply a pre-emergent to stop winter weeds
Put down a pre-emergent herbicide in October or November to keep winter weeds from sprouting. We recommend Nitro-Phos Barricade, which we’ve sold for years.
As temperatures cool, winter weed seeds fall onto your lawn and try to germinate. Barricade is a granular product that creates a barrier, hence the name, that keeps those seeds from sprouting. Spread it just like fertilizer, then water it in.
The fall application is one of four Barricade applications a year. Different weeds sprout in different seasons, so staying on the full program keeps weeds away all year.
Step 3: Prevent brown patch with Heritage G
Treat your lawn with Heritage G fungicide from late September to mid-October, before brown patch appears. Heritage G is a granular fungicide, applied much like fertilizer. We carry Heritage G at our office in Arcola.
Brown patch shows up as ugly brown or yellow circles in the yard once nighttime temperatures cool. Texas A&M AgriLife Extension notes that fungicides work best when applied preventively in the fall, before symptoms are visible (AgriLife Extension).
You can also treat after the spots appear. Either way, it takes two applications. Treating early has two big advantages:
- You never see the damage. Once spots appear, much of the damage is already done.
- You use about half as much product. Fungicides are expensive, and preventive rates are much lower than curative rates. Always follow the rates on the product label.
Houston fall lawn care calendar
| Task | Product | When to apply | Why |
|---|---|---|---|
| Prevent brown patch | Heritage G Fungicide (granular) | Late September to mid-October | Stops the fungus before spots appear, using less product |
| Fall fertilizer | Nitro-Phos Fall Special (8-12-16) | October and November | Feeds roots and stems before dormancy without forcing top growth |
| Pre-emergent weed control | Nitro-Phos Barricade (granular) | October and November | Blocks winter weed seeds from sprouting |
Frequently asked questions
All of our grass varieties are available now
We sell our St. Augustine grass sod by the piece at our office. Fall is also a great time to repair bare or damaged spots before winter. We have all varieties of our grass available at our farm, and ready to deliver freshly-harvested grass for your project.
While it’s still warm, we bring in smaller loads from our farm to keep the grass at our office fresh and green. Because the inventory at our office stays low, please call ahead at 281-431-7441 to make sure we have what you need. See our current grass sod prices.
We also carry Nitro-Phos Fall Special, Heritage G and Barricade at our office in Arcola. If you have questions about any of these products or your lawn, give us a call. We’re happy to help.
Related Links
- Texas A&M AgriLife Extension, St. Augustinegrass Lawn Management (EHT-144)
- AgriLife Today, Apply fall preemergence herbicide to avoid spring weeds (September 23, 2020)
- Texas A&M AgriLife Extension, Bexar County, Brown Patch Disease of Lawns
