When and What Type of Fertilizer Should I Use on My Lawn?

— Written By and last updated by

Answer: Now that spring has sprung and warm season grasses such as Bermuda, Centipede, Zoysia, and St. Augustine are flourishing, it is time to begin applying fertilizer. Each type of warm season grass needs different nutrients, with some needing more than others. It is best to obtain a soil sample analysis before making applications. Soil testing is more accurate than guessing. It eliminates the guesswork and the possibility of applying too much or too little product. In the event that soil testing has not been conducted, follow the guidelines below for your specific lawn.

 Fertilizer is made up of a ratio of nitrogen, phosphorus, and potassium. The first number represents nitrogen, the second number is phosphorus, and the third number is potassium. To determine the amount of nitrogen needed, divide the first number by one hundred. So if you were using 12-4-8, you would need to apply 8.3 pounds per thousand square feet. If needing to apply half a pound of nitrogen per thousand square feet, just divide the first number by fifty.

  • Bermuda Lawn: After green up apply one pound of nitrogen per thousand square feet from March through August every four to six weeks. Examples of a complete fertilizer to use are 12-4-8 or 16-4-8. A little bit of math is needed to determine exactly how much fertilizer to apply to meet the one-pound of nitrogen per thousand square feet.
  • Centipede Lawn: Do not apply any fertilizer until mid June. When making fertilizer applications, apply half a pound of nitrogen per thousand square feet of a high-level potassium fertilizer such as 5-5-15, 6-6-12, or 8-8-24. Typically only one application is needed per year, with exceptions to the coastal areas that may need another application in August to enhance performance. To determine the amount needed per thousand square feet, just divide the first number by fifty.
  • St. Augustine Lawn: Apply half a pound of nitrogen per thousand square feet using same fertilizer recommendation for Bermuda. Make application in May, June, and August, with the exception of applying one pound of nitrogen per thousand square feet in July.
  • Zoysia Lawn: Apply half a pound of nitrogen per thousand square feet three weeks after spring green up using the same fertilizer recommendation as Bermuda. Make another application in late June or early July, and again in mid August.

Reminder: If you would like to learn more about Horticultural related topics, then join the “Sampson County Friends of Horticulture”. This program offers monthly “How To” Horticultural Seminars. Please call (910) 592-7161 for more information. Please call the Sampson County Cooperative Extension Center at (910) 592-7161 with your horticultural questions and to register for any upcoming events. Be sure to check out the Ask An Expert Widget at sampson.ces.ncsu.edu for any questions you may have.

Written By

Photo of Della KingDella KingExtension Agent, Agriculture - Field Crops (910) 592-7161 (Office) della_king@ncsu.eduSampson County, North Carolina
Posted on Jun 11, 2013
Was the information on this page helpful? Yes check No close
This page can also be accessed from: go.ncsu.edu/readext?223196