Fertilizing a St. Augustine Lawn
How often does a St. Augustine lawn need to be fed?
St. Augustine can be a heavy feeding grass, particularly where their is plenty of rainfall and/or automated irrigation. Typically, it requires two to three feedings during a growing season, but may require more in regions where there is no dormant season.
What type of fertilizer should I apply to my St. Augustine lawn?
Before starting on any lawn fertilization program, it's best to have a soil test done. Test results can show you what nutrients are deficient and the pH of your soil. Saint Augustine thrives in a wide range of soil pH from 5.0 to 7.5 or so. Most nursery and garden centers sell testing kits or you can buy a soil testing kit online here. Your local extension service might also provide soil testing services.
Once your soil has been adjusted properly, you can then begin with a lawn fertilization program consisting of several applications of fertilizer per year.
The type of fertilizer you use will vary depending on the condition of your soil and the time of year. Soil types also influence fertilizer needs. Soil tests are required to determine phosphorus, potassium, calcium and other nutrient deficiencies.
Here's some general fertilization guidelines and recommendations for St. Augustine Lawns...
The First Application (Spring)
In areas where it goes dormant, when your St. Augustine has greened up by 50% or more in the early spring, it's time for the first application of fertilizer. For this first application, a fertilizer high in nitrogen is okay (the first number), however you want to make sure there is little or no phosphorus (the middle number) and plenty of potassium (the last number). Most nursery and garden centers stock 15-0-15 or 18-0-18 for St. Augustine lawns.
Second Application (Summer)
About 6 to 8 weeks after the spring application you can apply another dose of the same fertilizer used in spring.
Third Application (Fall)
In early fall, you'll want to apply a fall feed/winterizer fertilizer. This fertilizer will be low in nitrogen but high in potassium with maybe a little phosphorus. Potassium will help to build up the root system, helping to protect your grass from the harsh winter. The idea is to get the fertilizer down and watered in before the grass goes back into dormancy.
Several fertilizer brands out there mix in weed control products with the lawn fertilizer. This way you can kill two bugs with one stone, pun intended:-) Whatever nursery and garden center you do business with, it’s likely you’ll find fertilizers that contain a weed control product.
*NOTE: If using a 'weed and feed' to kill weeds in your St. Augustine lawn, always use one containing Atrazine for weed control.
Lawn Fertilization & Weed Control Program
Many local nursery and garden centers offer a do-it-yourself lawn care program. I'm not talking about the big box stores and Scotts brand products. That I am aware of. not a golf course in my area uses Scotts fertilizers. In my opinion, there are many better products on the market which are also less expensive.
Click here if you would like to see a Lawn Fertilization & Weed Control Program for a St. Augustine lawn that we provide to our customers at Wilson Bros. Nursery in mid-Georgia. The program uses golf-course grade Lebanon Pro Fertilizers.