As a landscaper who has designed countless lawns and gardens, I’m often asked by homeowners, “What type of grass is this?” When it comes to St. Augustine, its broad, flat blades and lush carpet-like growth make it one of the easier warm season grasses to identify. But there are subtle characteristics that set St. Augustine apart from other turfgrasses.
Over years of working hands-on with St. Augustine, I’ve come to recognize its distinctive features – from the way its thick stolons spread across the ground to its preference for hot, humid climates. In this article, we’ll take an in-depth look at the key visual and growth traits that set this popular turfgrass apart.
We’ll examine features like leaf width and color, underground growth habits, and active growing seasons. I’ll also overview the differences between common St. Augustine cultivars. Understanding the unique characteristics of this grass will help you identify it in your own lawn and distinguish it from similar turfgrasses.
Whether you’re considering planting St. Augustine or already have it established, learning the nuances of its appearance and growth will ensure you’re caring for it properly. Join me as we uncover the telltale signs that set St. Augustine apart. Let’s get growing!
What Are The Key Characteristics Of St. Augustine Grass?
Over the years, I’ve become intimately familiar with the look and feel of St. Augustine grass. This warm season turfgrass has some distinctive characteristics that help identify it. Getting to know St. Augustine’s visual and growth traits is key for proper care.
Dense, Thick-Bladed Foliage
The most obvious identifier of St. Augustine is its blade width. St. Augustine produces wide, flat leaf blades, often measuring 1/4 to 3/4 inches across. I like to describe them as long rectangles tapered to a point.
This broad blade gives the grass a very full, thick-bladed appearance. When mature, the turf is dense and lush. You can feel the health of St. Augustine in the springy cushion it forms underfoot.
St. Augustine’s leaves tend to lie relatively flat. The wider blades create a thick, coarse texture compared to slender grasses like bermuda. Up close, you’ll appreciate the stiff, leathery feel of St. Augustine’s foliage.
When actively growing, St. Augustine has a rich, blue-green color. It lacks the vivid dark green seen in grasses like emerald zoysia. The hint of blue visually distinguishes it.
In hot weather or drought stress, the grass takes on a yellowish-green, faded appearance. Proper irrigation and nitrogen fertilization brings back the characteristic blue-green hue.
The floral bracts on St. Augustine seed heads also have a purple-blue tint. So blue is truly the signature color of this grass.
Aggressive Spreading Habit
Left unchecked, St. Augustine aggressively expands sideways above ground via stolons. These long stems creep along the soil surface, rooting down at nodes. The stolons interweave to form a continuous mat.
You’ll also see St. Augustine expanding steadily outward underground through rhizomes. This active spreading habit enables St. Augustine to quickly fill in bare areas. But it also requires regular mowing and edging to contain.
Prefers Frequent Mowing
To maintain its lush appeal, St. Augustine requires frequent mowing with a sharp blade. The fast top growth necessitates cutting 1-2 times per week in peak season. Mowing height should be 3-4 inches.
Anything less than 2 inches causes St. Augustine to focus growth on lateral spread rather than upright leaf production. St. Augustine cut too short loses density and vigor.
Proper mowing stimulates thick, healthy turf growth. So willingness to mow frequently is key for maintaining attractive St. Augustine.
How To Identify St. Augustine Grass
When trying to determine if a turfgrass is St. Augustine, start by looking closely at the leaf blades. The width and shape of the foliage, along with stolon growth, are key identifiers.
Examine The Leaf Blades
Focus on the individual leaf blades first. St. Augustine produces wide, flat blades with a blunt tip. The leaf margins are relatively smooth, without serrations or ridges like Bermuda grass.
Typical dimensions for St. Augustine blades are 1/4 to 3/4 inches across, though cultivars like Bitterblue may be near an inch wide. I describe the shape as a broad rectangle that tapers slightly at the end.
You can feel the prominent midrib that runs the length of each blade. St. Augustine leaves tend to lie relatively flat in a horizontal orientation, unlike more upright grasses.
St. Augustine foliage has a stiff, leathery texture. The leaves feel hardy and rigid, not limp. This aids the grass in retaining its shape when mowed.
Note The Presence of Stolons
Also inspect the base where the leaf blade attaches to stems. You should see aggressive above-ground stolons forming a tangled mat across soil.
Identify where individual leaf blades connect to these thicker horizontal stems. Follow a stolon and you’ll notice leafy nodes rooting down. This network of interwoven stems allows St. Augustine to spread laterally.
So if you see broad, flat leaves emerging in different directions from wiry, interconnecting stolons, that’s a sign of St. Augustine.
Assess The Density Of Growth
Step back and look at the overall turf. Established St. Augustine forms a dense, thick carpet of grass. The broad leaf blades and proliferating stolons create a lush, full appearance.
There’s little exposed dirt or gaps between established plants thanks to rapid propagation through stolons and rhizomes. You shouldn’t be able to readily see the soil subsurface once the turf matures.
The spongy, cushiony nature of St. Augustine becomes apparent when walking across an established lawn. Overall, thickness with extensive ground cover is characteristic.
Using these visual cues, experienced eyes can reliably spot St. Augustine at a glance. Focus on leaf width and texture, stolon presence, and density of growth to identify this grass.
What Are The Differences Between St. Augustine Cultivars?
While all St. Augustine shares some common traits, there are noticeable differences among cultivars. Various selections have been bred over the years to enhance qualities like shade and drought tolerance.
Getting to know the unique features of each cultivar helps inform proper care and expectations. Here’s an overview of several popular types.
Raleigh St. Augustine
Introduced in 1980, Raleigh St. Augustine is prized for better drought hardiness over common St. Augustine. It has a medium-coarse leaf texture and forms a dense, high quality turf.
During drought stress, Raleigh exhibits less leaf firing compared to other cultivars in my experience. Its deeper root system gives Raleigh an advantage at extracting moisture from dry soils.
However, Raleigh lacks the shade tolerance of options like Palmetto or Seville. It performs best with at least 6 hours of direct sun per day. Raleigh retains the classic blue-green hue of traditional St. Augustine.
Palmetto St. Augustine
Palmetto is a semi-dwarf cultivar selected for its finer leaf texture and greater shade tolerance. It produces a noticeably thinner turf and smaller stolons than Raleigh.
I’ve found Palmetto thrives with as little as 3-4 hours of direct sunlight daily. It’s a great option for lawns under partial tree cover. Dappled sunlight and moderate shade are fine for Palmetto.
In addition to its shade adaptation, Palmetto also develops a deep root system. This enhances its drought tolerance once established. The trade off is a less lush appearance, but reduced irrigation needs.
Seville St. Augustine
Another shade and cold tolerant cultivar, Seville was bred in the 1990s. It has good shade tolerance comparable to Palmetto.
I’ve observed Seville thriving under oak trees and on shaded slopes. But it produces a denser, thicker turf than Palmetto. Seville forms a resilient, spongy mat and handles foot traffic well.
Seville also boasts better cold hardiness than most other St. Augustine varieties. Its smaller stolons survive winters better, greening up earlier in spring. Seville’s finer texture appeals to northern gardeners needing shade and cold tolerance.
Bitterblue St. Augustine
Known for its fast growth and lightly blue-green color, Bitterblue tolerates cold better than Raleigh. It spreads rapidly via thick stolons and rhizomes.
Bitterblue has wider leaf blades nearing an inch across. It forms large, visible stolons above ground. Below ground, vigorous rhizomes fuel its fast growth and spread.
While cold hardy, Bitterblue lacks drought and shade tolerance. It needs full sun and ample moisture to look its best. Prepare for frequent mowing and edging to control its robust growth habit.
Sapphire St. Augustine
Sapphire is a deep blue-green cultivar prized for its color intensity and disease resistance. It has good drought tolerance but only average shade adaptability.
Sapphire forms a very dense, fine bladed turf resistant to common diseases. I’ve found its rich color to be highly attractive, though it fades under poor conditions. Sapphire’s resilience and deep roots aid its vigor.
Consider your specific climate, soil, and site conditions when selecting among the many St. Augustine cultivars available today. Matching the variety to your environment ensures success.
How Does St. Augustine Compare To Other Warm Season Grasses?
With its broad blades and thick, spreading growth, St. Augustine is distinctly different from other common warm season grasses. Understanding where it overlaps and varies aids identification.
St. Augustine Versus Bermuda Grass
Bermuda has a much finer leaf texture than St. Augustine. Its slender, pointed blades typically measure 1/10″ across or less. Bermuda forms a tight, dense mat but lacks the sprawling stolons of St. Augustine.
The growth patterns also diverge. Bermuda grows vertically, with leaf nodes stacked along upright stems. St. Augustine features horizontal spreading via above ground stolons and runners.
In my experience, Bermuda withstands drought stress better than St. Augustine thanks to very deep rooting. St. Augustine leverages lateral growth to survive drought. But it browns faster than Bermuda.
While both like sun and heat, St. Augustine needs more water and fertilizer compared to hardy Bermuda to look its best. Bermuda’s dormancy also lasts longer over winter.
St. Augustine Versus Zoysia Grass
Zoysia shares the stiff, coarse texture of St. Augustine but has much finer blades. Underfoot, zoysia feels like a prickly carpet compared to St. Augustine’s spongy cushiness.
St. Augustine primarily spreads above ground via stolons. Zoysia lacks notable stolon growth but expands steadily through rhizomes. Vertically, zoysia grows in bunches while St. Augustine forms a uniform mat.
St. Augustine breaks dormancy and greens up earlier in spring than zoysia. Its active growth period starts about a month sooner. Zoysia needs full sun, while St. Augustine tolerates moderate shade.
While both require frequent watering, mature zoysia has better drought tolerance than St. Augustine. Zoysia also excels at crowding out weeds once established.
Shared Warm Season Traits
St. Augustine overlaps with Bermuda and zoysia in preferring warm temperatures, humidity, and abundant moisture for peak performance. All three grasses thrive during the long summers of the southern U.S.
Like St. Augustine, Bermuda and zoysia go dormant after the first frost in northern climates. They share excellent heat tolerance and an aggressive, spreading growth habit when conditions are ideal.
But the visual differences in texture, blade width, color, and density set St. Augustine apart from its warm season counterparts.
When Is St. Augustine Grass Most Actively Growing?
Like all warm season grasses, St. Augustine follows an annual cycle of vigorous growth and winter dormancy. Understanding its ideal growing temperatures helps determine when St. Augustine greens up and enters peak performance season.
Waking Up In Spring
During my years of caring for St. Augustine lawns, I’ve found spring greenup begins once overnight lows stay above 55°F consistently. This usually occurs in March/April across the St. Augustine grass zone.
Soil temperature triggers the grass to break dormancy. St. Augustine remains brown and dormant as long as nighttime temperatures drop to 50°F or below.
In spring, St. Augustine greens up earlier than alternatives like zoysia. You’ll see its signature blue-green hue weeks before zoysia or bermudagrass break dormancy. This gives St. Augustine a jumpstart on the growing season.
Peak Growth in Summer
Once awakened from dormancy, St. Augustine enters a phase of vigorous growth and spreading. The hottest, most humid months from May through September are peak season for St. Augustine.
Daytime highs of 80-95°F are ideal for rapid lateral expansion by stolons. Humidity levels exceeding 60% provide ample moisture for lush growth.
St. Augustine flourishes during summer’s heat and humidity across the southern climate zone. Its growth rate noticeably accelerates compared to spring and fall.
Mowing frequency increases to every 5-7 days to keep up with aggressive growth. Fertilization and irrigation needs also rise to maximize growth during peak season.
Preparing for Dormancy
With the arrival of cooler autumn temperatures, St. Augustine begins hardening off in preparation for winter dormancy. Growth rate and spreading decline noticeably.
The grass often exhibits some fall discoloration as chlorophyll breaks down. St. Augustine slows its metabolism as day lengths shorten and temperatures drop.
Once the first frost hits, lasting below 32°F for multiple hours, St. Augustine goes dormant. Its straw-brown color persists until warm spring temperatures revive it again.
Adjusting Care by Season
Recognizing seasonal changes in St. Augustine growth allows you to tailor maintenance appropriately. Reduce mowing, watering, and feeding as growth slows in fall. Resume full care in spring once greenup occurs.
By working with its biological rhythms, you can maximize St. Augustine’s performance during prime growing months and minimize upkeep as it rests each winter.
What does St. Augustine sod look like?
As a landscaper who has installed countless rolls of St. Augustine sod, I can easily recognize its distinctive appearance. Freshly harvested sod contains visible stolons interweaving through the thick mat of grass.
The sod has a sectioned, rectangular shape with clean cut edges on all sides. Looking closely, you’ll notice the underside contains a mesh of roots that anchored the grass before harvest.
The color is a rich blue-green when actively growing or yellow-green if harvested during dormancy. The flat, broad leaf blades create a coarse texture and spongy feel.
Overall, the sod roll resembles a dense, living carpet. It’s thicker and more substantial than finer grassed like Bermuda. You can clearly see the stolon matrix holding the sod together.
What does St. Augustine seed look like?
St. Augustine grass is propagated vegetatively, not through seeds. Each plant spreads laterally via above ground stolons and below ground rhizomes.
If you find a vendor selling St. Augustine “seed” online or in stores, it’s likely either Bermuda grass seed or some other warm season grass mixture. Always verify the species with the seller.
Genuine St. Augustine cultivars like Raleigh, Palmetto and others do not produce viable seeds. The seed heads contain only sterile floral parts.
So be skeptical if you encounter St. Augustine seed for sale. While stolons or plugs can be used to plant St. Augustine, seed is not an option. This grass does not set seed.
What does St. Augustine grass feel like?
Of all the warm season grasses, St. Augustine provides the plushest, most cushy texture underfoot. The sprawling stolons form a dense, resilient mat over soil.
Walking across an established St. Augustine lawn feels soft and supportive. The stiff, thick blades cushion and conform to the shape of your foot with each step.
The foliage itself feels thick and fibrous, stiffer than Bermuda or zoysia leaves. St. Augustine resists being crushed or smashed down. There’s a smooth, velvety feel when you brush your hand across it.
Between the springy lawn and pleasantly coarse texture, St. Augustine creates a sublime tactile experience. It’s instantly recognizable by foot as well as sight.
After reading this guide, you now have an in-depth understanding of the visual characteristics and growth habits that make St. Augustine grass so distinctive. From its broad, flat blades to its preference for hot, humid climates, St. Augustine stands apart from other turfgrasses.
While all St. Augustine shares some common traits, I hope you’ve learned how cultivars like Raleigh, Palmetto and Seville vary in their shade tolerance, texture, color and growth rate. Recognizing these nuances will help you select the ideal type for your unique conditions.
With knowledge of St. Augustine’s seasonal cycles, you can also tailor maintenance to maximize its performance during peak growing months while minimizing upkeep when it’s dormant.
Most importantly, you can now confidently identify St. Augustine based on its leaf width, prominent midrib, aggressive above-ground stolons and sprawling, dense carpet-like coverage. Keep an eye out for St. Augustine’s hallmarks as you walk or drive around your neighborhood.
I invite you to reference this visual guide whenever you need help distinguishing St. Augustine from similar turfgrasses. Use the knowledge you’ve gained to care for your St. Augustine properly and leverage its strengths for a thriving warm season lawn.