Saint Augustine grass has a gorgeous blue-green color when grown properly. It is popular in warm, humid regions including the Southeastern United States, Mediterranean and Gulf of Mexico because it grows well in many soils and salty conditions. Saint Augustine is relatively low-maintenance but is susceptible to frost damage, pest problems, turf buildup and spongy turf. The best way to make Saint Augustine grass green is to fertilize it, water when needed and keep weeds at bay.
Get a fertilizer that is high in nitrogen. This nutrient promotes green, thick grass. The package will have three numbers: nitrogen-phosphorus-potassium. Choose one with a larger first number. If some of the nitrogen is in slow-release form, it's even better for St. Augustine grass.
Feed your lawn in the very beginning of spring, once the grass turns green. Spread the fertilizer two to six times, depending on the instructions on the package. Apply the food through fall.
Allow for one-half pound of water-soluble nitrogen for 1,000 square feet of lawn. Slow-release food requires more--1 pound per 1,000 square feet.
Keep St. Augustine grass 3.5 to 4 inches tall. This is the healthiest height for the greenest grass. Shorter blades will result in shallower root growth, more stress on the plant and potential pest problems.
Supplement water if you notice Saint Augustine grass wilting. Give it one-half to three-fourth an inch.
Keep weeds away because they ruin the look of Saint Augustine grass. Use a weed killer formulated for this type of grass. A pre-emergence herbicide should be applied before new growth in the early spring. It will kill crabgrass. Post-emergence herbicides will fight grassy weeds if applied in the early summer, before the weather gets too hot.