The Definitive Guide: St. Augustine Grass

An Overview

St. Augustine grass (Stenotaphrum secundatum), also known as ‘Carpetgrass’, is native to the Gulf of Mexico coast lines, the West Indies and Western Africa. Records from long ago have reported the presence of St. Augustine grass as a seashore pioneer along the Atlantic coasts of Africa and the Americas. Prior to 1800, the species was reported in Uruguay, Brazil, Nigeria, Sierra Leone, the West Indies, Bermuda and South Carolina. It was even reported in Kauai, Hawaii prior to 1800. By 1840, St. Augustine grass had also been collected from Australia and New Zealand further highlighting its adaptability and utility around the world.

Characteristics and Traits of St. Augustine Grass

St. Augustine provides a coarser, denser ground cover than most fine textured Bermuda grasses, thus giving it the nickname ‘Carpetgrass’. It is an aggressively growing grass, yet it is still able to be controlled around its borders by edgers of various types. Because St. Augustine seldom produces viable seeds, it is most often planted via plugs, sprigs, or rolls of sod, with sod being the most desirable option available. It does require more moisture, in the soil and in terms of watering, than other turfgrass options. Therefore St. Augustine is best suited for naturally humid areas such as Florida, Texas, and other southern states with subtropical to tropical weather.

Additionally, most varieties of St. Augustine are known to be fairly shade tolerant, making it an attractive option for when turf grass is desired under large shade trees. It tolerates a wide range in soil types, but cannot withstand being waterlogged or droughty sites. In the United States, St. Augustine grass can be found from the Carolinas to Florida and westward along the Gulf Coast to Texas and in Southern and Central California. Because of its lack of winter hardiness, St. Augustine grass is restricted to areas with mild winter temperatures. Similar to bermudagrass, St. Augustine thrives in high temperature and high humidity zones, but the growth of St. Augustine is better than that of bermudagrass in cool, coastal climates. As a species, there are many cultivars and varieties to choose from that have varying pros and cons so as to be a good choice for many site conditions.

Varieties of St. Augustine Grass and their Differences

Since St. Augustine grass has been propagated for the past 200 years, only a few strains or varieties have evolved and none have been developed (1). The following are just a few available varieties and their primary characteristics:

• Floratam – This variety of St. Augustine grass is the only option that is not shade tolerant. For this reason it is a popular choice for Florida homeowners with their often sunny yards.

• Bitter-Blue – Is a variety that is a good choice for shady sections of lawn. It is also one of the more cold tolerant varieties to choose from.

• Seville – Offers a blue-green, long leaf blade with good color retention. It is also tolerant of shade, salt, and short periods of drought conditions. Another benefit of the Seville variety is that it is tolerant of the cinch bug, a common pest of St. Augustine. However, it lacks the cold tolerance that would allow it to be used beyond the southern boundaries of the Gulf Coast.

• Sapphire – Another variety that offers beautiful deep blue-green color and a softer texture than most St. Augustine varieties. It is considered suitable for warmer climates and is desirable in coastal regions for its salt tolerance along with being shade and drought tolerant.

• Palmetto – A coastal option for both warm and cooler climates is the Palmetto variety of St. Augustine grass. It can tolerate the cold better than other varieties as well and can thrive in either partial shade or full sun settings. It is one of the varieties that can resist the cinch bug.

What are the advantages and disadvantages of St. Augustine Grass?

As is often true in the horticultural world, a plant’s strongest assets can also be its worst characteristics. No turfgrass is ideal for all circumstances, and St. Augustine grass is no exception. As shown by the traits of just a few of the varieties listed above, St. Augustine grass has a variety for nearly every site condition in the southern United States.

Advantages:

• Shade tolerant
• Sun tolerant
• Warm to Hot Humid Climates
• Has varieties that can withstand cooler temperatures
• Its dense growth habit can tolerate average amounts of foot traffic and withstand weed infestations
• Quick growing in most locations
• Some varieties are resistant to cinch bugs

Disadvantages:

• Repeated foot traffic will cause wear spots
• The blue-green color will turn brown in winter
• Even varieties that tolerate shade will not grow as densely as they would in sun
• Aggressive growth habit means it can spread quickly and must be maintained to say in desired areas
• Requires monthly fertilizer and proper soil pH amendments
• Must keep turf cut to 3”-4” high as cutting too short will cause grass to thin
• Vulnerable to numerous lawn pests such as cinch bugs, gray leaf spot, large patch and take-all root rot

St. Augustine Grass and Lawn Maintenance

With warm-season grasses, month-by-month lawn care occurs on a different timetable than cool-season northern grasses that peak during fall. Saint Augustine grass is best planted in spring, after the final frost, as warm-season grasses come out of dormancy and enter prime growth. Overseeding existing turf lawns with additional St. Augustine seed can also be done at this time.

Basic tips for getting your St. Augustine turf lawn off to a good start:

• Plant your sod or plugs during a cooler part of the year to avoid stressing the plants.
• Water your grass during the early morning hours to minimize evaporation.
• Mowing is a necessary stress that all grasses are able to tolerate, but each variety has a preferred mowing height; St. Augustine’s is 3 to 4 inches.
• Know which variety of St. Augustine you have in your lawn to be sure of proper care

Still unsure of how to best care for your Saint Augustine lawn? Check out your state’s agricultural extension office for helpful tips and soil testing kits that will help you determine your best lawn care plan.

If you live in the southern or warm coastal United States and your lawn needs call for a durable and wear-resistant warm-season lawn that can withstand both heat and drought, Saint Augustine may be the perfect solution providing you seasons of bright green turf grass.

Sources:

1. Duble, Richard L. Texas Coorperative Extension https://aggie-horticulture.tamu.edu/plantanswers/turf/publications/staug.html

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