Most carpet manufacturers recommend professional hot-water extraction every 12 to 18 months to keep the warranty valid. In Southwest Florida, that's the minimum, not the target. Sand tracked in from the beach acts like sandpaper inside the pile, and year-round humidity means moisture and odors linger in carpet far longer than they would up north.
For a typical household with no pets and shoes off at the door, once a year is fine. Add a dog or a cat, kids, or a lanai door that's open half the day, and every six months keeps carpet looking and smelling right. Vacation rentals and homes with heavy seasonal use should be extracted between busy stretches, not just when they look dirty.
Between professional cleanings, vacuum high-traffic areas two or three times a week with a machine that has a working beater bar, and blot spills immediately with a white towel rather than scrubbing them. Scrubbing spreads the stain and frays the fiber.
One more Florida-specific note: run the air conditioning or fans after a deep clean. Carpet that stays damp in a humid house is where mildew smells start. We tell every customer how long their carpet needs, and we're available 24/7 if you want to schedule a clean before company arrives.