Bermuda grass is a warm-season variety known for its aggressive growth habit, making it a heavy feeder that requires consistent nutrient support. This turf creates a dense, durable lawn that recovers rapidly from heavy use or stress. To maintain thickness and deep green color, a regular fertilization regimen is necessary throughout its active growing season. The frequency of applications depends primarily on the type of fertilizer product used and the overall length of the season.
Establishing the Fertilization Window
The time frame during which Bermuda grass should receive fertilizer is defined by soil temperature, not the calendar date. The feeding window opens when the soil temperature, measured at a depth of four inches, consistently reaches 60 to 65 degrees Fahrenheit. This threshold signals the grass is exiting dormancy and beginning its vigorous growth phase, commonly called “green-up.”
Monitoring this temperature can be done using a soil thermometer or by checking local extension office websites. Applying fertilizer before the grass is actively growing is wasteful because dormant roots cannot absorb nutrients efficiently. The active feeding window remains open through the summer and closes in the fall when soil temperatures consistently remain below 60 degrees Fahrenheit. Fertilizing after this point can stimulate tender new growth that is susceptible to damage from the first hard frost.
Determining Frequency Based on Product Type
The most significant factor determining how often you fertilize is the nitrogen release rate of the product you select. Nitrogen is the primary nutrient Bermuda grass uses for shoot growth and color, and its availability dictates the necessary application intervals. Nitrogen sources are typically categorized as quick-release or slow-release, each requiring a different schedule.
Quick-Release Fertilizers
Quick-release fertilizers contain water-soluble nitrogen (WSN) and provide an immediate surge of nutrients, resulting in rapid green-up. However, this nitrogen is quickly consumed or leached, meaning the effect is short-lived. To maintain color uniformity, these products necessitate more frequent applications, typically every four to six weeks throughout the active growing season.
Slow-Release Fertilizers
Slow-release fertilizers utilize water-insoluble nitrogen (WIN) and are designed to break down gradually over time. This provides a stable and sustained supply of nutrients, avoiding the intense growth spikes and subsequent fading associated with quick-release sources. Using a slow-release product extends the application interval to every six to ten weeks, reducing the total number of applications needed per year.
For a typical growing season (early May to late September), a quick-release schedule might require five applications, while a slow-release product generally reduces the requirement to three or four. For example, feeding a lawn in May, July, and September with a slow-release product often provides sufficient nutrition. The choice depends on the desired level of maintenance and managing the burn risk associated with quick-release options.
Essential Pre-Application Steps
Before applying any fertilizer, conduct a professional soil test to determine the existing nutrient profile and pH level of your lawn. This test is mandatory for a heavy feeder like Bermuda grass to ensure you are not over-applying phosphorus (P) or potassium (K).
The results of the soil test guide the selection of the correct fertilizer analysis, preventing the unnecessary addition of non-nitrogen nutrients. Accurately measuring the lawn area is necessary to calculate the precise application rate. Recommendations advise applying no more than one pound of actual nitrogen per 1,000 square feet in a single application.
You must calculate how much granular product is required to deliver that one pound of actual nitrogen, based on the nitrogen percentage listed on the bag. For example, if a bag is labeled 20-5-10, it contains 20% nitrogen by weight, meaning five pounds of that product equals one pound of actual nitrogen. Accurately measuring and calibrating your spreader ensures the correct amount of nutrient is distributed evenly.
Post-Application Care and Error Prevention
Immediate care following fertilization is necessary to maximize the product’s effectiveness and prevent damage to the turf. All granular fertilizers, especially those containing quick-release nitrogen, must be watered into the turf immediately after application. Watering prevents chemical burn by washing the fertilizer prills off the leaf blades and moving the nutrients into the soil where the roots can access them.
Even slow-release products require watering to initiate the release mechanism and begin the nutrient breakdown process. A common mistake is applying too much product in one area, which results in a concentration of salts that draws moisture from the grass, causing chemical burn or scorching. Another frequent error is uneven application, often due to improper spreader settings or overlapping passes, which results in an unsightly pattern of dark green stripes across the lawn. Wait at least 24 to 48 hours after applying fertilizer before mowing to allow the granules to dissolve completely and the nutrients to begin absorption.