St. Augustine grass (Stenotaphrum secundatum) is a warm-season turfgrass favored for creating a thick, dense lawn, particularly in tropical and subtropical climates of the southern United States. It is recognized for its broad, coarse, blue-green blades and its better-than-average shade tolerance compared to other warm-season varieties. St. Augustine grass spreads rapidly using above-ground runners, called stolons, which allows it to form its characteristic lush, carpet-like appearance. Successful establishment depends on meticulous site preparation and the correct installation method.
Preparing the Planting Site
Creating an optimal environment for the new grass to root is the first step toward a healthy lawn. The entire area must be cleared of existing weeds, debris, and old turf, either through mechanical removal or by applying a non-selective herbicide at least two weeks before planting. This preparation ensures the new grass material makes solid contact with the native soil, which is required for successful root development.
Once the area is clear, the soil should be loosened, or tilled, to a depth of several inches to allow for easy root penetration and improve drainage. St. Augustine grass thrives in well-drained soil and prefers a pH range between 6.0 and 7.5 (slightly acidic to neutral). A soil test determines if amendments, such as lime or sulfur, are necessary to adjust the pH level before planting. Incorporating organic material, like compost, into the topsoil prior to leveling can enhance nutrient availability and structure for the new roots.
Selecting and Installing Spreading Materials
St. Augustine grass is propagated vegetatively because it does not produce commercially viable seed; therefore, it must be established using sod, plugs, or sprigs. Each method uses the grass’s natural spreading mechanism—the stolon—to eventually cover the intended area. The choice among them balances immediate coverage against cost and establishment time.
Sod Installation
Sod offers the fastest path to a finished lawn, providing immediate, dense coverage, though it is the most expensive option. To install sod, strips must be laid in a staggered, brick-like pattern, ensuring the edges are tightly butted together without overlapping. Roll or tamp the newly laid sod immediately to eliminate air pockets and press the roots firmly against the prepared soil. This tight contact encourages the roots to quickly grow down into the soil.
Plugs Installation
Plugs are small sections of established turf, offering a more economical alternative to sod with an intermediate establishment time. Planting involves digging holes roughly 3 inches deep and 3.5 inches wide, spaced at intervals ranging from 6 to 18 inches apart. The plug must be firmly pressed into the hole, ensuring the top is level with the surrounding soil surface. Closer spacing, such as 6 to 8 inches, leads to a faster fill-in, often within two to four months, while wider spacing takes longer.
Sprigs Installation
Sprigs, which are pieces of stolons without soil, are the least expensive option but require the longest time to establish a full turf. They can be broadcasted over the prepared soil surface or planted in shallow furrows. Sprigs should be lightly covered with a thin layer of soil, ensuring at least one-third of the plant material remains exposed to the light. Immediately after planting, the area should be lightly rolled to ensure good soil-to-sprig contact, which is necessary for the exposed stolons to root.
Post-Planting Care for Successful Establishment
The first few weeks after installation are important for the grass to transition to a rooted, established lawn. Watering is the most important factor during this establishment period to prevent the new material from drying out. New sod, plugs, or sprigs require frequent, shallow watering to keep the upper soil layer consistently moist. This often requires watering two to three times per day for the first seven to fourteen days.
After the initial period, watering frequency should be gradually reduced while the duration is increased to encourage deeper root growth. For example, after two weeks, watering can be reduced to once per day, then to every other day, until the grass receives approximately one inch of water per week. New roots should be checked by gently lifting a corner of the sod or tugging on a plug. The presence of white, feathery roots extending into the soil indicates successful establishment.
Applying a starter fertilizer, which is rich in phosphorus, shortly after installation encourages the development of a strong root system. Phosphorus is beneficial for root growth, helping the new grass anchor itself. Mowing should not begin until the grass material is firmly rooted and shows signs of growth, which usually takes two to three weeks. When the first cut is made, the mower blades should be set to the highest recommended height for St. Augustine grass (typically 2.5 to 4 inches), and no more than one-third of the leaf blade should be removed.