Ask five people how often a Florida lawn needs mowing and you will get five answers. The honest one is that it changes through the year — and the properties that look best are the ones where the schedule changes with it.
The one-third rule
The rule that actually governs everything else is simple: never remove more than one third of the grass blade in a single cut. Cut more than that and you shock the plant. It responds by dumping energy into regrowing leaf instead of root, which leaves the lawn thinner, more drought-sensitive and more vulnerable to weeds for weeks afterwards.
Work backwards from that rule and the schedule sets itself. If St. Augustine is being maintained at four inches, you cut it when it reaches about six. In June, with heat and afternoon storms, it will get there in five to seven days. In January, it might take three weeks.
What that means season by season
From roughly April through October — the growing season on the Treasure Coast — most St. Augustine and Bahia lawns need a weekly cut. From November through March, growth slows enough that every two weeks is usually plenty, and in a dry January you may stretch further than that. The mistake is holding a bi-weekly schedule through July, which forces a cut that violates the one-third rule every single visit.
Cut height matters as much as frequency
St. Augustine wants to be tall — three and a half to four inches, and higher in shade. Bahia does well at three to four inches. Zoysia can go shorter, around two to two and a half. Cutting any of them down to golf-course height is one of the fastest ways to ruin a Florida lawn: short grass means less leaf surface, shallower roots, more soil temperature at ground level, and an open invitation to every weed in the neighbourhood.
A few habits that make more difference than frequency
Keep the blade sharp — a dull blade tears the leaf tip, which browns off and makes the whole lawn look dull a day after cutting. Vary your mowing direction between visits so the grass is not always pushed the same way. And avoid cutting a wet lawn where you can; it clumps, it compacts, and it spreads fungus across the yard on the mower deck.