How to Fertilize & Take Care of St. Augustine Grass


St. Augustine grass grows in many warm, humid regions such as the coastal parts of the Mediterranean and Gulf of Mexico. Not only does the variety stand up well to salt and shade, it can be grown in many types of soil. St. Augustine grass is distinct because it has a blue-green color that only gets more saturated as you fertilize it. Feeding the lawn regularly creates a manicured appearance.

Step 1

Pay attention to the nitrogen content in fertilizer. Nitrogen creates greener, healthier foliage. This element is the first number listed on the packaging, followed by phosphorus and potassium. The ideal blend will have at least some nitrogen in a slow-release form, so it continues to feed the grass.

Step 2

Fertilize St. Augustine grass beginning when it turns green in the spring. Apply it two to six times until the end of fall. Water soluble food will take more applications than slow release fertilizer. Follow the application instructions on the packaging. Fertilizing too early or too late in the season can damage the grass.

Step 3

Apply 1/2 pound of nitrogen per 1,000 square feet of St. Augustine grass. If you're using a slow-release food, apply 1 pound per 1,000 square feet.

Step 4

Mow St. Augustine grass to a height of 3.5 to 4 inches. If you mow it shorter, the grass will lose its ability to handle stress, there may be pest problems and the roots will grow too shallow. Set your mower to the highest wheel height setting.

Step 5

Water St. Augustine grass if it shows signs of wilting. Add 1/2 to 3/4 inch of water. Hold off on watering until it wilts again.

Step 6

Remove weeds with an herbicide made for St. Augustine grass. Apply a pre-emergence herbicide to deal with crabgrass from previous seasons. Spray it in the late winter or early spring, before new growth begins. Apply post-emergence herbicides in the early summer to control grassy weeds.

Tips and Warnings

  • Do not remove more than 1/3 of a leaf blade at any one time.

Things You'll Need

  • Fertilizer
  • Mower
  • Water
  • Herbicides


  • University of Florida IFAS Extension: St. Augustine Grass for Florida Lawns
  • Texas A&M University: St. Augustine Grass
Keywords: St. Augustine grass, fertilize grass, care for grass

About this Author

Kelly Shetsky has been a broadcast journalist for more than 10 years, researching, writing, producing and reporting daily on many topics. In addition, she writes for several websites, specializing in medical, health and fitness, arts and entertainment, travel and business. Shetsky has a Bachelor of Arts in communications from Marist College.