Published October 18, 2026
Fertilizing your own lawn in Central Texas can work well, as long as you get the soil test, the rate and the timing right. A lawn treatment program earns its keep when weeds keep coming back, because the pre-emergent windows are narrow and the wrong product can hurt St. Augustine. Here is what a DIY plan has to get right, using Texas A&M AgriLife Extension's numbers.
A lawn treatment program is worth it when the problem is weeds or timing, and often not when the lawn is already thick and healthy. AgriLife's bermudagrass lawn calendar notes that older lawns with established cover and well-developed roots may not need as much fertilization, and that a dense, healthy lawn is the best defense against weeds.
So the question is less "pro or DIY" and more "can you hit the dates and rates every year". The sections below are the checklist.
Test the soil before buying anything. AgriLife's bermudagrass calendar says to test at least every other year, and the St. Augustinegrass guide says every 1 to 3 years, with every nutrient except nitrogen applied based on the results. That way you only add the phosphorus or potassium the test says is missing.
The rate is where DIY most often goes wrong. AgriLife says not to exceed 0.5 to 1 lb of nitrogen per 1,000 square feet in any single application. Its bermudagrass calendar also gives a shortcut: a bag that says it covers 4,000 square feet usually delivers 0.8 to 1.0 pound of nitrogen per 1,000 square feet when spread as directed.
More is not better. Too much nitrogen makes the lawn grow fast for a few weeks after feeding, which AgriLife says can lead to scalping and piles of clippings. For St. Augustine, the guide puts quick-release nitrogen at no more than 1 pound per 1000 square feet per application, and notes 0.5 pound may prevent burning.
Returning clippings counts toward that. AgriLife's mowing guide says clippings are usually 2 to 4 percent nitrogen and can cut the need for supplemental nitrogen by up to half. Our mowing maintenance leaves them on the lawn for that reason.
Timing matters as much as rate. AgriLife says not to fertilize Bermuda before full spring green-up, in hot dry stretches of late summer, or in late fall as it heads into dormancy. For St. Augustine, the first feeding waits until the lawn has been mowed at least twice in spring, and the last goes down at least 4 to 6 weeks before the area's historic first frost.
The National Weather Service Austin climate summary puts the average first freeze at December 1, so the last feeding of the year belongs somewhere between the third week of October and the first days of November. Skip any application with heavy rain forecast in the next 24 hours, and sweep stray granules off the driveway back into the grass.
Weed control is the part that is hardest to get right on your own, for three reasons.
AgriLife also says to find out why the turf is thinning before treating weeds at all. Weeds move into thin grass, so a lawn that is short on sun, water or the right mowing height will keep losing ground no matter what gets sprayed.
Yellow St. Augustine is not always hungry for nitrogen. AgriLife's St. Augustine guide says the grass is very sensitive to iron deficiency and often yellows in alkaline soils above pH 7.5. A soil test tells you where your yard stands, and a foliar iron spray corrects that, and more fertilizer will not.
If your lawn is thick, you will run a soil test and you can hit the spring and fall windows every year, a DIY plan is reasonable. Always follow the label, which AgriLife repeats for every fertilizer and herbicide. If weeds are the problem, or you would rather not track the dates, our lawn treatment service times fertilization and weed control to the season and to the grass you actually have.
CTX Mowing times fertilization and weed control to the season and to the grass in your yard, alongside the mowing. Get a free quote today.
