Most lawn advice is written for places with four real seasons. Houston has a long hot one, a short cool one, and about three weeks of spring in between, and a lawn treated on a northern calendar spends the whole year slightly out of step.
February and March are for cleanup and patience. Cut back the beds, clear the winter debris, and resist the urge to fertilize the moment it warms up — feeding St. Augustine before it is actively growing mostly feeds the weeds. Wait until the grass has fully greened up, usually early April.
April through September is the growing season, and it is relentless. Weekly mowing is not overkill, it is the minimum if you want to stay under the one-third rule: never remove more than a third of the blade in one cut. Raise the mower for summer, because taller grass shades its own roots and holds moisture through the worst of August. Scalping a St. Augustine lawn in July is how you end up with bare patches by September.
October and November are the second cleanup window. Leaves come off the turf before they mat down through the wet months, beds get weeded and re-mulched, and the last few cuts come down slightly in height. December and January the lawn mostly rests — which makes it the right time for the projects that are miserable in summer heat: bed reshaping, new plantings, edging, and stone work.
The single biggest difference between a good Houston lawn and an average one is not the products. It is cutting on a schedule, at the right height for the month, with the blade sharp. Everything else is a smaller adjustment on top of that.