Fertilizing St. Augustine Grass: A Comprehensive 9-Step Guide

Introduction

St. Augustine grass (Stenotaphrum secundatum) is a popular warm-season turfgrass known for its lush green color, adaptability to various soil conditions, and resilience to drought and heat. Fertilizing is crucial for maintaining the health and vigor of St. Augustine lawns, ensuring optimal growth and resistance to pests and diseases. This comprehensive 9-step guide will equip homeowners and lawn care professionals with the knowledge and techniques necessary for successful fertilization of St. Augustine grass.

Understanding the Nutrient Needs of St. Augustine Grass

St. Augustine grass requires a balanced supply of essential nutrients to thrive, including nitrogen (N), phosphorus (P), and potassium (K). Nitrogen is primarily responsible for vegetative growth and leaf development, while phosphorus promotes root growth and overall plant health. Potassium strengthens plant cell walls, improves water retention, and enhances drought tolerance.

According to the National Gardening Association, the ideal N-P-K ratio for St. Augustine grass is 3:1:2. This means that for every 1 pound of nitrogen applied, 1/3 pound of phosphorus and 2/3 pound of potassium should be provided.

Choosing the Right Fertilizer

The first step in fertilizing St. Augustine grass is selecting the appropriate fertilizer. Choose a fertilizer specifically formulated for warm-season grasses, such as those containing slow-release nitrogen sources like urea or methylene urea. Avoid fertilizers with high levels of phosphorus, as excessive phosphorus can lead to soil nutrient imbalances and environmental concerns.

Determining the Application Rate

The application rate of fertilizer depends on the nitrogen content of the fertilizer and the desired level of growth. As a general rule, apply 1 pound of nitrogen per 1,000 square feet of lawn area. For example, a fertilizer with a nitrogen content of 32% would require 3.1 pounds of fertilizer per 1,000 square feet.

Choosing the Application Method

There are two primary methods for applying fertilizer to St. Augustine grass: broadcast spreading and spot feeding. Broadcast spreading involves distributing fertilizer evenly over the entire lawn area using a spreader. Spot feeding involves applying fertilizer directly to specific areas, such as thin or discolored patches.

Timing the Fertilizer Application

Fertilize St. Augustine grass during the active growing season, typically from spring to fall. Avoid fertilizing during periods of extreme heat or drought, as this can stress the grass and lead to nutrient burn.

Frequency of Fertilizer Application

St. Augustine grass generally requires three to four fertilizer applications per year, spaced according to the following schedule:

• First application: Early spring (March or April)
• Second application: Mid-summer (June or July)
• Third application: Early fall (September or October)
• Fourth application (optional): Late fall (November or December)

Additional Tips for Fertilizing St. Augustine Grass

• Water the lawn thoroughly after fertilizing to dissolve and distribute the nutrients.
• Avoid overfertilizing, as it can lead to nutrient burn and other lawn problems.
• Use a soil test to determine the pH level of your soil and adjust the pH to the optimal range for St. Augustine grass (6.0 to 7.0).
• Aerate the lawn to improve water and nutrient penetration.
• Keep the lawn height between 2.5 and 3 inches to promote healthy growth.
• Mow the lawn regularly to stimulate tillering and density.

Conclusion

By following these 9 steps, homeowners and lawn care professionals can ensure the proper fertilization of St. Augustine grass, leading to a lush, healthy, and resilient lawn. By understanding the nutrient needs of the grass, choosing the right fertilizer, determining the application rate and method, timing and frequency of fertilization, and adhering to additional tips, lawn owners can maintain a vibrant and attractive St. Augustine lawn for years to come.

Table 1: Recommended N-P-K Ratio for St. Augustine Grass

Table 2: Fertilizer Application Rates for St. Augustine Grass

Table 3: Fertilizer Application Schedule for St. Augustine Grass

Table 4: Advantages and Disadvantages of Different Fertilizer Application Methods