How to Fertilize St. Augustine Grass


St. Augustine is a cultivated perennial turf grass grown widely in warm and sub-tropical climates because of its tolerance for heat and occasional cold exposure. It propagates itself vegetatively by sending out creeping stolons along the soil surface and by seed. St. Augustine grass is used most commonly as ornamental lawn grass and not as a sports turf, as it does not recover quickly from heavy foot traffic. In addition, fertilizer applications of iron sulfate can help keep the grass green when growing in alkaline soil.

Step 1

Feed St. Augustine grass once per month or once every other month during the peak growing season from spring through fall. Feed lush lawns that are green and growing on a nutrient rich soil bed every other month. Fertilize lawns that are growing on nutrient poor soil monthly.

Step 2

Apply a nitrogen-rich granular lawn fertilizer according to the dosing directions on the package, not to exceed 1 lb. of fertilizer for every 1,000 square feet of lawn expanse.

Step 3

Spread the fertilizer by walking the lawn with a drop spreader set to the rate recommended on the fertilizer label. Alternatively, wear garden gloves and cast the fertilizer by hand over the lawn at the recommended distribution rate.

Step 4

Water the lawn until it is drenched after fertilizing to nestle the fertilizer granules into the soil surface and begin to push the nutrients down to the roots.

Step 5

Spray the St. Augustine grass with an iron sulfate product to correct yellowing discoloration from iron deficiency due to alkaline growing soil. Apply and repeat according to product label directions to green up the St. Augustine grass.

Tips and Warnings

  • Avoid excess fertilizer application as it can cause build-up of thatch. This can rob the grass roots of water and nutrients.

Things You'll Need

  • Granular lawn fertilizer
  • Drop spreader
  • Gloves
  • Iron sulfate


  • Texas A&M University: St. Augustine Grass
Keywords: fertilizer for St. Augustine grass, feeding perennial St. Augustine lawns, nitrogen fertilzer for grass lawn

About this Author

An omni-curious communications professional, Dena Kane has more than 17 years of experience writing and editing content for online publications, corporate communications, business clients, industry journals, as well as film and broadcast media. Kane studied political science at the University of California, San Diego.