St. Augustine grass is a warm-season turf known for creating a thick, dense, and lush lawn, especially in hot and humid climates. It spreads aggressively using above-ground runners called stolons, which allows it to form a desirable carpet-like appearance. While the idea of planting a lawn from seed is appealing for its simplicity and cost, St. Augustine grass is a notable exception to this rule. Growing St. Augustine grass from seed is not the standard, reliable, or commercially available method for establishing this turf.
The Reality of St. Augustine Seeds
St. Augustine grass (Stenotaphrum secundatum) does produce seed heads, but these seeds are not a practical or commercially viable option for establishing a lawn. The majority of desirable St. Augustine cultivars are either sterile or produce seeds with very low germination rates. This low viability means planting the seed results in a patchy, inconsistent lawn, which is the opposite of the uniform turf the grass is known for.
Furthermore, varieties that might produce a viable seed often do not breed true to the parent plant, leading to a mix of undesirable grass types. Seed production is also economically infeasible, as the amount of seed produced is too low to harvest, process, and sell affordably on the commercial market. For these reasons, you will not find St. Augustine grass seed sold in garden centers or online retailers, forcing propagation to rely entirely on vegetative methods.
Planting St. Augustine Using Plugs or Sod
Since seed is not an option, St. Augustine grass must be established through vegetative means, primarily using sod or plugs. Sod provides an instant lawn, consisting of pre-grown sections of turf rolled onto prepared soil. For successful installation, the soil surface must be moist before laying. Pieces should be placed tightly together with staggered seams, similar to a brick pattern. After laying, the sod should be rolled to ensure complete contact between the roots and the underlying soil.
Plugs offer a more cost-effective but slower alternative, involving planting small, established pieces of turf into the ground. To plant plugs, use a tool like an auger bit to dig holes the same size as the plug, typically 3 inches deep. Plugs are spaced between 6 and 18 inches apart, depending on the desired speed of coverage. Closer spacing fills in the lawn faster.
Each plug must be pressed firmly into the hole so the top is level with the surrounding soil. This eliminates air pockets around the roots that could cause the plug to dry out.
Optimal Conditions for Successful Establishment
The best time to plant St. Augustine grass is during the active growing season, typically late spring or early summer. Planting when the soil is warm and the risk of frost has passed allows the grass to establish a robust root system before temperature extremes. Prior to planting, prepare the area by clearing debris and tilling the top 4 to 6 inches. Ensure the soil has a slightly acidic to neutral pH, ideally between 5.0 and 7.5.
A starter fertilizer, which is typically rich in phosphorus to support root development, can be applied to the soil before laying sod or directly into the plug holes. The most important factor immediately following installation is the watering regimen to encourage rapid root growth. New sod or plugs require consistently moist soil for the first two to three weeks, necessitating multiple, short watering cycles daily. After this initial period, gradually reduce the watering frequency and increase the duration to encourage deeper root growth, transitioning to the schedule of an established lawn.