The answer to 'how to maintain grass' is to follow a regular lawn care routine that includes mowing, watering, fertilizing, and overseeding. Proper mowing height, watering frequency, and fertilizer application are key to keeping your lawn healthy and lush. Regular overseeding can also help fill in bare spots and thicken the grass.
It's important to mow your lawn at the recommended height for your grass type, typically 3-4 inches. Avoid cutting more than 1/3 of the blade height at a time. Water your lawn deeply 1-2 times per week, applying about 1 inch of water each time. Fertilize 2-3 times per year with a slow-release fertilizer, following the product instructions. Overseed in the fall to introduce new grass seed and fill in any thin or bare areas.