St. Augustine grass is a popular choice for warm-season lawns, known for its lush, dense turf that thrives in humid climates. Propagating this grass can cost-effectively establish new areas or repair bare patches. This guide provides insights into successfully propagating St. Augustine grass.
Understanding St. Augustine Grass Propagation
St. Augustine grass is primarily propagated vegetatively, meaning it grows from parts of the plant rather than from seeds. Its seeds are often sterile or not viable, making propagation from seed unreliable. Instead, the grass spreads through stolons, which are above-ground runners that root at their nodes to form new plants. This natural spreading habit makes vegetative propagation highly effective.
The most common methods for propagating St. Augustine grass involve using plugs or sprigs. Plugs are small, rooted sections of sod, typically 2-4 inches in diameter, planted into the desired area. Sprigs are individual stolons or runners, often cut into smaller pieces, then placed into the soil. Both methods leverage the grass’s natural ability to spread and establish new growth, contributing to a consistent and uniform lawn.
Best Time for Propagation
Timing is important for successful establishment. The ideal period for propagation is during the warm, active growing season, typically from late spring through early summer. Consistent temperatures and adequate moisture levels during this time support faster establishment and robust root development. Soil temperatures should be consistently above 55°F, ideally ranging from 70°F to 80°F, to encourage vigorous growth.
Planting too early in spring, when temperatures are still cool, can delay establishment and increase frost damage risk. Propagating too late in summer or fall might not allow enough time for the grass to establish a strong root system before cooler weather arrives.
Gathering Materials and Site Preparation
Successful propagation requires thorough site preparation and gathering necessary materials. You will need St. Augustine grass plugs or sprigs, a shovel or trowel, a soil-plugging tool (optional), a watering can or hose, organic matter like compost, and a suitable fertilizer.
First, clear the designated area of any existing weeds, debris, or old grass. This can involve hand-pulling, raking, or using a non-selective herbicide at least two weeks prior. Next, loosen the soil several inches deep with a rake or tiller to improve aeration and root penetration. Incorporate organic matter, such as compost, to enhance soil fertility and drainage. St. Augustine grass prefers a slightly acidic to neutral soil pH, ideally between 6.0 and 7.5, which can be assessed with a soil test.
Propagating St. Augustine Grass
Once the site is prepared, begin propagation using either plugs or sprigs. For plugs, space them 12 to 18 inches apart in a staggered or diamond pattern. Dig holes slightly larger than the plug’s root ball, deep enough so the top sits level with the surrounding ground. Gently place each plug into a hole, firming the soil around it to ensure good contact.
When using sprigs, plant them in shallow furrows or broadcast them over the prepared soil. If planting in furrows, create rows about 6 inches deep and lay the sprigs end-to-end, covering them with a thin layer of soil while leaving some leaf blades exposed. If broadcasting, scatter the sprigs evenly, then lightly cover them with about half an inch of soil or compost. Immediately after planting, thoroughly water the entire area to settle the soil and provide initial moisture.
Post-Propagation Care
Consistent care is crucial for establishing newly propagated St. Augustine grass. Immediately after planting, keep the soil consistently moist for the first 7 to 14 days, watering daily or as needed. This frequent, light watering helps new roots establish without drowning them. After this initial period, gradually reduce watering frequency to promote deeper root growth, aiming for 1 to 1.5 inches of water per week through deep, infrequent irrigation once established.
Delay fertilization until the grass shows signs of rooting and active growth, typically 6 to 8 weeks after planting. Use a fertilizer specifically formulated for St. Augustine grass to provide essential nutrients, especially nitrogen, which encourages leaf and shoot growth. When the new grass reaches a mowable height (3-4 inches), perform the first mow at the highest setting on your mower to avoid stressing the young growth. Monitor for weeds and remove them promptly by hand to prevent competition for resources, as herbicides can harm young grass.