A Guide To Grow And Care For St Augustine Grass

This grass is a favored choice for lawns in tropical and subtropical areas, especially in the southern United States, Texas, Mexico, and Central and South America. Its appeal lies in its lush look, ability to withstand heat, and knack for out-competing weeds.

While it's not commonly grown from seeds, St. Augustine grass is usually planted using sod, plugs, or sprigs. It's not typically grown indoors but rather in outdoor areas where it can get enough sunlight and moisture to flourish.

When To Plant

The best time to plant St. Augustine grass is in spring or summer when there's plenty of sunlight, giving it at least 90 days to establish before the first frost. Avoid planting during the winter when frost is present, and make sure the soil temperature is above 55 degrees Fahrenheit.

Where To Plant

St. Augustine grass thrives in warm, humid conditions, commonly found in the southern United States. However, it can also grow in cooler regions if planted in a sheltered spot with proper care. It prefers temperatures between 80 and 90 degrees Fahrenheit.

It's typically grown outdoors for lawns, pastures, and coastal yards due to its ability to handle heat, humidity, and soil salinity. It's commonly used in warm areas like Florida and the Gulf States.

St. Augustine grass is not particularly difficult to care for, but it does require some level of consistent maintenance to thrive. While it tolerates varying conditions, proper care ensures optimal growth and health. Here are some care requirements for growing them:

Light

While St. Augustine grass can tolerate partial shade, it thrives best in full sunlight, receiving at least 6 to 8 hours of direct sunlight per day. Adequate sunlight promotes photosynthesis, which is essential for the grass to produce energy and grow vigorously. In shady areas, the grass may become thinner and more susceptible to disease and pest issues.

Soil

St. Augustine grass prefers well-draining soil with a pH level between 5.0 and 8.0. It can tolerate a variety of soil types, including sandy, loamy, and clay soils, as long as they are well-drained.

Adding organic matter like compost or peat moss to the soil can improve its fertility and drainage, promoting healthier growth.

Watering

Keep the soil consistently moist, especially during periods of hot weather. Water deeply and infrequently to encourage deep root growth and avoid shallow rooting. Aim to provide about 1 inch of water per week, either through rainfall or irrigation.

Temperature

St. Augustine grass is a warm-season grass that thrives in temperatures between 80 to 90 degrees Fahrenheit. It can tolerate high temperatures well but may struggle in extremely cold conditions.

Planting St. Augustine grass in the spring or summer when temperatures are warmer allows for optimal establishment before the onset of winter frost.

Humidity

These types of grass are well-suited to humid climates and thrive in areas with moderate to high humidity levels. Adequate humidity helps the grass retain moisture and reduces water stress during periods of heat or drought.

However, excessive humidity combined with poor air circulation can increase the risk of fungal diseases, so proper lawn maintenance practices are essential to prevent issues.

Fertilization

The best time to fertilize St. Augustine grass is in late spring or early summer, usually around May or early June. It's suggested to use ½ to 1 pound of actual nitrogen per 1,000 square feet, adjusting depending on your soil type.

Mowing

Regular mowing is essential to keep St. Augustine grass healthy and visually appealing. Set your mower blade to a height of 2.5 to 4 inches and mow frequently enough to remove no more than one-third of the grass height at a time.

Weed Control

The grass has good natural weed-suppressing abilities, but occasional weed infestations may still occur. Use pre-emergent herbicides in early spring to prevent weed seeds from germinating, and spot-treat any existing weeds with post-emergent herbicides labeled safe for use on St. Augustine grass.

Aeration and Dethatching

Periodically aerate your lawn to alleviate soil compaction and improve air and water penetration to the roots. Additionally, dethatch the lawn as needed to remove excessive thatch buildup, which can hinder nutrient uptake and water infiltration.

St. Augustine grass can be propagated using different methods, but plugging is the most common and straightforward. Plugging involves planting small squares or plugs of existing St. Augustine grass, which gradually spread and fill the gaps between them.

Another method of propagating is sprigging, where grass stolons are planted with a thin layer of soil covering them. This method involves leaving the grass blades exposed to encourage rooting.

For plugging propagation, you may use a grass plugging tool (optional), along with nutrient-rich soil if necessary, and a water source for regular watering.

Growing St. Augustine grass from seed is uncommon and challenging because it primarily spreads through stolons (runners), plugs, or sod. While this grass does produce seeds, they are often sterile or produce seeds infrequently, making seed propagation unreliable.

Typically, those who prefer growing St. Augustine grass from seed are often home gardeners or professionals who are experimenting with different propagation methods. However, it's essential to understand that successful germination and establishment from seed can be unpredictable.

St. Augustine grass is vulnerable to cold weather because it lacks a protective mechanism against freezing temperatures. Among warm-season turfgrasses, it's the least tolerant to cold.

When temperatures drop below freezing, St. Augustine grass can turn brown and suffer permanent damage. Here's how to protect it from cold weather:

• Irrigation: Ensure the soil has enough moisture before a freeze, but stop watering early to prevent ice formation on leaves.
• Covering: Use blankets or boxes (avoid plastic) to cover vulnerable plants during freezing temperatures, removing the covers once they warm up.
• Mowing: Avoid mowing frozen grass and maintain a higher mowing height to encourage deeper root growth and create a warmer environment.
• Traffic: Prevent foot or vehicle traffic on frozen grass to minimize damage.

Bermuda grass and St. Augustine grass are both warm-season turfgrasses but are different species with distinct characteristics. While they share some similarities, they are often confused due to their common use on lawns, parks, and recreational areas.

These two grasses have distinct differences in appearance, shade tolerance, cold tolerance, drought resistance, fertilizer needs, propagation methods, weed resistance, price, and maintenance requirements. Key differences include:

• Appearance: Bermuda grass has a finer texture and a more uniform, dense appearance compared to the wider leaf blades and less dense growth habit of St. Augustine grass.
• Shade Tolerance: Bermuda grass tolerates shade better than St. Augustine grass, although neither grass performs well in heavy shade.
• Cold Tolerance: Bermuda grass is more cold-tolerant than St. Augustine grass and can withstand frost and freezing temperatures better.
• Drought Resistance: Bermuda grass is more drought-tolerant than St. Augustine grass and can survive extended periods of drought with minimal water.
• Fertilizer Needs: Bermuda grass typically requires more frequent fertilization than St. Augustine grass to maintain its color and density, especially in high-traffic areas.
• Propagation: Bermuda grass is commonly propagated from seed, while St. Augustine grass is typically propagated from plugs, sod, or sprigs.
• Weed Resistance: Bermuda grass has better weed resistance than St. Augustine grass, as its dense growth habit helps to suppress weed growth.
• Price Difference: Bermuda grass seed is generally less expensive than St. Augustine grass sod or plugs.
• Maintenance: Bermuda grass requires more frequent mowing and maintenance than St. Augustine grass, especially during the growing season.

St. Augustine grass does have some drawbacks, but these drawbacks don't necessarily mean that people avoid growing it altogether. Instead, they serve as considerations that individuals should be mindful of before planting to ensure successful growth and maintenance.

By understanding these drawbacks, individuals can take proactive measures to mitigate potential issues and properly care for their St. Augustine grass lawns.

• It has relatively high water requirements compared to some other turfgrasses.
• While St. Augustine grass responds well to fertilization, it requires regular applications of fertilizer to maintain its health and vigor. 
• Grass is prone to certain pests and diseases, including chinch bugs, brown patches, and gray leaf spots.
• In shaded areas, it may become thin and sparse, requiring more frequent overseeing or alternative turfgrass species.
• In some regions, St. Augustine grass has the potential to become invasive and outcompete native vegetation, particularly in coastal areas where it can spread aggressively into adjacent habitats.
• They are sensitive to cold temperatures and can suffer damage or die back during harsh winters, particularly in regions where freezing temperatures are common.

St. Augustine grass primarily refers to the species Stenotaphrum secundatum, but there are several cultivars or varieties within this species. Some common types of St. Augustine grass include:

• Floratam: Floratam is one of the most popular cultivars of St. Augustine grass, known for its vigorous growth, lush appearance, and good resistance to pests and diseases.
• Palmetto: Palmetto St. Augustine grass is prized for its shade tolerance, making it an excellent choice for lawns with partial shade.
• Raleigh: Raleigh St. Augustine grass is another popular cultivar known for its dense growth, dark green color, and ability to tolerate a variety of soil types.
• Seville: Seville St. Augustine grass is valued for its fine texture, dense growth, and tolerance to heat and drought.
• Delmar: Delmar St. Augustine grass is a newer cultivar known for its improved disease resistance and durability.

These are just a few examples of St. Augustine grass cultivars. The most suitable option for a specific garden or landscape may vary depending on factors such as climate, soil type, sunlight exposure, and maintenance preferences.

St. Augustine grass is susceptible to pests such as chinch bugs, armyworms, and sod webworms, as well as diseases like brown patches, gray leaf spots, and take-all root rot. If signs of pests or diseases are observed, appropriate control measures should be taken promptly. 

Pests

Bugs such as chinch bugs are attracted to grass that's not doing well, which can happen if the grass is stressed from things like not getting enough water, not being taken care of properly, or not getting the right nutrients.

• Chinch Bugs: These insects target weakened St. Augustine grass by injecting a toxin that leads to grass death. To prevent them,
  • Keep an eye out for signs of drought stress and promptly water the lawn when necessary.
  • Avoid excessive watering to prevent waterlogged, oxygen-deprived soil.
  • Opt for resistant varieties like "Floratam" to lower susceptibility.
• Nematodes: These tiny roundworms consume plant tissue, disrupting water and nutrient absorption. To prevent,
  • Promote healthy roots by adjusting the mower deck height, providing regular fertilization, and aerating the lawn. 
  • Refrain from excessive nitrogen applications to prevent prioritizing leaf growth over root development.
• Ground pearls: These pests feed on roots, appearing in spring and summer with pearl-like bodies. To treat them,
  • Choose improved St. Augustine grass varieties with resistance to chinch bugs, which can deter ground pearl infestations.
  • Maintain proper irrigation, fertilization, and drainage practices to discourage these pests.
• Armyworms and cutworms: These insects feed on crowns and leaf blades near the soil surface, causing circular patches. To prevent, 
  • Implement regular irrigation and fertilization routines.
  • Ensure adequate lawn drainage to prevent overly wet conditions, which favor the presence of these pests.

Diseases

Diseases like gray leaf spots thrive when they're humid, and St. Augustine's decline can spread through tools or grass pieces that are contaminated. When the grass is stressed from things like drought, heat, or not getting watered right, it's easier for diseases to take hold.

• Take-All Root Rot (TARR): Symptoms include grass blades turning yellow, turf thinning out, and irregular brown patches appearing. They can be treated by ensuring the soil is well-drained, maintaining regular watering, removing thatch buildup, and aerating the lawn.
• Fairy Ring: Symptoms occur when grass develops large circular brown patches. Promote proper soil aeration, ensure regular watering, and remove thatch to manage the fairy ring.
• Gray Leaf Spot: Symptoms include leaves developing oval spots with dark brown borders. Treatment can be done by applying fungicides containing azoxystrobin and thiophanate-methyl, to avoid excessive watering to control gray leaf spots.
• St. Augustine Decline (SAD): This disease is caused by the panicum mosaic virus, resulting in grass death. There is no specific cure; a focus on effective lawn maintenance practices to bolster grass immunity against St. Augustine's decline.