A fall feeding helps a North Texas lawn go into winter strong. Fed too late, it does more harm than good.
The short version:
- Bermuda and Zoysia: last nitrogen by about October 1 in Dallas–Fort Worth.
- St. Augustine: go light and early, or skip it.
- Dormant grass: don’t feed it.
- Winterizer: get a soil test before you buy one.
The DFW cut-off: October 1
Texas A&M AgriLife says the final late-season nitrogen should go down no later than 6 weeks before the expected first frost.
AgriLife’s table puts Dallas’ average first frost around November 16. That makes the last day for nitrogen about October 1. These are averages, so your yard may frost a little earlier or later.
Why feed in fall at all? AgriLife says late-season nitrogen helps a lawn resist winter weeds, keeps fall color, and helps spring recovery. Keep it modest. AgriLife says 1 pound of nitrogen per 1,000 square feet or less. Always follow the product label.
Missed the date?
If it’s past early October, skip nitrogen this fall.
AgriLife’s Bermudagrass calendar says it isn’t appropriate to fertilize in late fall and winter, when lawns are going dormant. Feed again in spring, once the grass is actively growing.
St. Augustine needs extra care
St. Augustine’s big fall problem is large patch. It’s a disease that leaves brown, circular patches. AgriLife says it starts in October and November in Texas, once temperatures drop below 70°F.
Late fall fertilizer makes it worse. AgriLife lists over-fertilization late in the fall and over-watering among the conditions that bring it on. It says large patch is especially bad in lawns that are poorly drained and over-fertilized.
For St. Augustine, AgriLife says the last nitrogen should go down at least 4 to 6 weeks before the first frost. Too much in fall can lead to more winter kill and disease.
Zoysia gets large patch too, so keep its fall feeding light.
What we do: in our program, St. Augustine gets no fall nitrogen at all. That’s our call, and it’s more careful than AgriLife’s minimum.
What about winterizer fertilizer?
“Winterizer” bags are usually sold as high in potassium. Your lawn may not need it.
AgriLife says to add phosphorus and potassium based on your soil test. Nitrogen is the one nutrient you don’t need a test for. When the soil already has enough phosphorus and potassium, AgriLife says to use a nitrogen-only fertilizer.
No recent soil test? AgriLife suggests a ratio of about 4 to 6 parts nitrogen, 1 part phosphorus and 2 to 4 parts potassium, like a 16-4-8.
Get a soil test
A soil test tells you what your lawn actually needs. AgriLife calls it easy and inexpensive.
The Texas A&M Soil, Water and Forage Testing Laboratory tests mailed-in samples. Your county Extension office has sample bags and instructions. Late summer or early fall is a good time to do it.
Don’t forget the winter weed barrier
Fall is also when winter weeds sprout. AgriLife says to put down a fall pre-emergent when the soil cools to about 70°F. In Texas, that’s usually September or October. Go by soil temperature, not the same calendar date every year.
The targets are winter weeds like annual bluegrass (poa annua), rescuegrass, henbit, chickweed and Carolina geranium. Our pre-emergent timing guide covers it in detail.
A fall feeding on Bermuda and Zoysia also helps the grass crowd out winter weeds.
Want it handled?
The September visit in our 9-visit lawn program does both jobs. We put down a different kind of pre-emergent aimed at winter weeds, and feed Bermuda and Zoysia for a strong fall finish. St. Augustine rests.
A licensed applicator picks products labeled for your grass type. Ask for a free weed control and fertilizer quote in Mansfield, Tarrant and Johnson counties.