Somewhere along the way, adding lime became generic lawn advice, the thing you do in fall because that is what people do. In much of the country that makes sense. Across the Big Bend, on centipede, it is frequently the wrong move, and applying lime without a soil test is one of the more common ways people create a problem that then takes a couple of seasons to unwind.
What pH actually controls
Soil pH does not feed the plant. What it does is determine which nutrients in the soil are chemically available for roots to take up. Iron, manganese, zinc and phosphorus availability all shift with pH, and the shifts are not subtle.
That means a lawn can be sitting in soil with plenty of iron and still show iron deficiency, because at the wrong pH the iron is locked in a form the plant cannot use. Adding more iron fertilizer treats the symptom while the underlying condition stays put.
Centipede wants acidic soil
This is the crux. Centipede is adapted to acidic, low-fertility soil, which is exactly what much of North Florida naturally provides, and it is why centipede became the default home lawn grass here in the first place.
Centipede generally prefers a soil pH in the acidic range, somewhere around 5.0 to 6.0. Push it up toward neutral and centipede develops iron chlorosis: the leaves go yellow between the veins while the veins stay green, growth slows, and the lawn thins. People see the yellowing and reach for nitrogen, which makes it worse, and the whole thing turns into what gets called centipede decline.
So applying lime to centipede without knowing your pH is a genuine risk. You may be creating chlorosis in a lawn that was fine.
When lime is appropriate
There are real cases. If a soil test comes back showing pH well below what your grass wants, lime raises it. Some soils around here are genuinely very acidic, and some grasses, St. Augustine and zoysia among them, tolerate and sometimes prefer a somewhat higher pH than centipede.
The point is not that lime is bad. The point is that lime is a specific correction for a specific measured condition, not a routine maintenance item.
Get an actual soil test
Your county extension office handles soil testing, and UF/IFAS Extension does this routinely for homeowners. It is inexpensive and it is the only way to know what you have.
To take a good sample, pull small cores from a dozen or so spots across the lawn, four inches deep, mix them in a clean plastic bucket, and submit from that composite. Sampling one spot tells you about one spot. Keep areas that behave differently separate, so the shaded back yard and the full-sun front are not blended into an average that describes neither.
Tell the lab what you are growing. Recommendations for centipede differ from recommendations for St. Augustine, and a generic turf recommendation may steer you wrong.
If you do need to change pH
To raise it, lime is the standard material, and dolomitic lime also supplies magnesium if the test shows you need it. It works slowly, over months, so apply based on the test recommendation and then retest the following year rather than applying repeatedly and overshooting. Overshooting is much harder to fix than undershooting.
To lower it, elemental sulfur is the usual material, applied at the rate the test recommends, and it also works slowly. Some nitrogen sources have an acidifying effect over time as well, though that is a slow secondary effect rather than a tool.
Either way, follow the product label for rates and timing, and do not try to make a large correction in a single application.
The iron shortcut, and its limits
If centipede is yellowing and pH is on the high side, a chelated iron application will green it up temporarily and is a reasonable stopgap that does not add nitrogen. It is a cosmetic fix, not a correction, and if the pH stays high the yellowing returns.
What it does buy you is time to make the actual adjustment properly rather than panicking and dumping nitrogen on a grass that does not want it.
Other things a soil test tells you
Beyond pH, a test reports phosphorus, potassium and other nutrient levels. On many established North Florida lawns, phosphorus is already adequate, which means a lot of complete fertilizer is supplying something the lawn does not need. Knowing that lets you buy a fertilizer that matches your soil instead of a generic ratio.
Test every two or three years for an established lawn, and before any renovation or new sod. Reach out if you want help making sense of a test result once it comes back.