St. Augustine grass (Stenotaphrum secundatum) is a popular warm-season turfgrass known for creating a thick, dense lawn in tropical and subtropical climates. This species is highly valued for its distinctive blue-green color and superior shade tolerance compared to many other warm-season grasses. Its vigorous lateral growth, spreading through above-ground runners called stolons, quickly forms a carpet-like turf. This dense growth helps crowd out weeds, leading homeowners to seek the best way to establish this durable groundcover.
Why St. Augustine Seed is Not Used
While St. Augustine grass produces seed heads, the seed is not a commercially viable method for establishing a lawn. Many desirable turf varieties, such as ‘Floratam’ or ‘CitraBlue’, are sterile or produce seeds with extremely low fertility. Even when viable seeds are produced, the overall yield is very low, making mass production impractical for the consumer market.
The seeds are also encased in a corky material on the spike, which makes harvesting and cleaning difficult for bulk sale. Furthermore, the resulting grass often has inconsistent turf quality, failing to guarantee the dense, uniform look homeowners expect. Therefore, St. Augustine grass is propagated entirely through vegetative means, using a piece of the existing plant to start new growth.
The Three Successful Planting Methods
Since seed is not an option, establishment relies on three vegetative methods: sod, plugs, and sprigs.
Sod provides the quickest results but comes at the highest financial cost. It involves laying down pre-grown mats of grass, offering an instant lawn and immediate protection against erosion and weed competition.
Plugs are small, individual pieces of rooted grass planted in a grid pattern across the soil. This method is significantly more cost-effective than sod and requires less intensive labor during planting. However, plugs can take two months to a full year to completely fill in a lawn, depending on spacing and growing conditions.
Sprigs, or stolons, are the runners of the grass that are shredded and broadcast over the soil. This represents the lowest material cost, but it demands the highest labor and maintenance, as the individual runners must be kept moist and protected. Like plugs, establishment from sprigs is slow, requiring patience as the runners root and spread to form a solid turf. Choosing an option depends on balancing the budget against the desired speed of establishment.
Preparing the Site and Initial Care
Site Preparation
Proper site preparation is necessary regardless of the chosen planting method. Existing turf and weeds should be removed, either physically with a sod cutter or chemically with a non-selective herbicide. A soil test should be conducted to determine pH and nutrient levels, as St. Augustine grass thrives best in a slightly acidic to neutral range (ideally 6.0 to 7.5).
Based on the test results, amendments like lime or elemental sulfur can be incorporated. The soil should be tilled to a depth of at least six inches to break up compaction and improve drainage. A phosphorus-rich starter fertilizer should then be applied to encourage robust root development before planting.
Initial Care
After planting, the initial care phase is crucial for successful establishment. For the first seven to fourteen days, the new grass requires frequent, shallow watering to keep the roots moist. This often means watering multiple times daily until the roots begin to “peg down” into the underlying soil.
The first mowing should be delayed until the sod or plugs are firmly rooted, usually 14 to 21 days after installation. The cut should be set to the highest setting to avoid stressing the new growth. Nitrogen-heavy fertilizers and herbicides should be avoided for the first 30 to 60 days, allowing the developing root system to focus on establishment rather than excessive leaf growth.