Augustine grass (also known as Charleston grass in
South Carolina) is often the most popular choice for
lawns throughout southern United States. Especially
in coastal regions where cold temperature extremes
are moderated by oceanic climatic conditions. St.
Augustine grass is native to the Caribbean, Africa
and Mediterranean regions, and best adapted to
for coastal regions, thrives in heat, does poorly in
cool climates. Excellent to fair under drought
conditions. Moderately good to heavy traffic.
Somewhat shade tolerant. Can be used in moist,
semi-fertile soils. At the moment, most common
installation method is sodding or plugs; seeds are
very difficult to obtain if not impossible.
HIGHLIGHTS: Compared to finer textured grasses
like the bermudas, St. Augustine has large flat
stems and broad coarse leaves. It has an attractive
blue-green color and forms a deep, fairly dense
turf. It spreads by long above-ground runners or
stolons. While it is aggressive, it is easily
controlled around borders. It produces only a few
viable seed and is commonly planted by sod, sprigs,
or plugs. St. Augustine grass is a big thatch
producer, more so than other types of grass. It also
requires plenty of moisture and is best suited to
humid regions. Has good shade tolerance, except for
Floratam. Susceptible to fungal diseases. St.
Augustine grass Decline is a virus common to Texas
and Louisiana and there is no known control.
Cold Tolerance: Poor (damage possible below 20)
Shade Tolerance: tolerates moderate levels of
shade, but will become thin under dense shade
Traffic Tolerance: Poor
Rate of Establishment: Medium/Fast
Planting: sod or plugs
Watering: needs weekly watering for optimal
appearance, but will survive drought conditions
Mowing Height: 2" — 4"
Common Pests: grubs, chinch bugs, mole
crickets, sod webworms, armyworms and cutworms.
Thatch: heavy producer of thatch made from
WARNING: an ingredient in many weed/feed
products (2,4-D) designed for cool-season grasses,
can kill St. Augustine.
Why won't my grass grow under the tree? I have the
best St. Augustine type.
The reason for the general poor performance is a
lack of, or alteration of, sunlight. The light
quality is diminished because trees absorb the same
light needed by grass, and since the trees get to it
first, they get the most. In addition, trees affect
the intensity and duration of light on the turf.
with a dense overhead canopy also have a denser root
structure that absorbs more moisture from the soil,
leaving less for the grass.
alter conditions by moderating temperatures,
leveling out the highs and lows, decreasing wind,
increasing humidity and intensifying competition for
water and nutrients. As a result, turf experiences
reduced shoot density, more upright growth,
increased plant height, decreased root depth and
thinner leaves and cell walls, causing fewer
carbohydrates to develop in the cell walls, reducing
photosynthesis and transpiration rates and making
them more susceptible to disease. In other words,
grass doesn't do too well under trees.
of the semi-dwarf types have excellent shade
tolerance relative to the coarse-type St. Augustine
grasses and other warm-season grasses. We also know
that the semi-dwarf varieties do not possess chinch
bug resistance, and those planting this grass will
need to use insecticides to control infestations
when they occur.
FLORATAM ST. AUGUSTINE GRASS FOR SHADY, MODERATE
Floratam St. Augustine grass was released by the
Florida and Texas Agricultural Experiment Stations
in 1972 as a SAD virus and chinch bug resistant
selection. It has since been observed to be brown
patch tolerant. Like other Florida types, Floratam
is a vigorous, coarse textured St. Augustine grass
variety. Stolons of Floratam are large, purplish-red
in color (demand this characteristic when purchasing
sod) with internodes averaging 3 inches in length.
Leaf blades are wider and longer than common St.
Augustine grass. According to James Beard, TAEX Turf
Researcher, tests at A&M concluded it is the most
drought-tolerant of all St. Augustine grasses.
is not as cold tolerant as common St. Augustine, so
preconditioning by use of Winterizer fertilizer
(3-1-2 or 4-1-2 ratio) in the fall (October) is
CRITICAL. Floratam may suffer freeze damage.
study of the drought tolerance of grasses entitled:
" Comparative Intraspecies and Interspecies Drought
Resistance of Six Major Warm-Season Turfgrass
Species" by S. I. Sifers and J. B. Beard, Texas A&M
Their findings were: Four years of field drought
resistance studies have been completed on a modified
sand root zone. In the fourth year of the study, 29
Bermuda grass, 2
seashore pespalum, 2 Buffalo Grass,
8 St. Augustine grass, 6 Centipede grass,
and 11 Zoysia grass
cultivars were subjected to 158 days of progressive
water stress with no supplemental irrigation applied
and less than 7.5 cm of natural rainfall. Degree of
leaf firing was used as an indicator of dehydration
avoidance and post-drought shoot recovery was used
as the indicator for drought resistance.
Significant drought resistance differentials were
found across the cultivars and among the species.
Results were consistent with the first three years
of this study among the Bermuda grass, seashore
pespalum, St. Augustine grass, and Buffalo grass
cultivars. Among the Centipede grass cultivars only
Oklawn fully recovered. Leaf firing of all Zoysia
grass cultivars was in excess of 50%. All recovered,
except Meyer at 20% and Belair at 45% after 30 days.
Excellent dehydration avoidance was seen in Floratam
and Floralawn St. Augustine grass. There were large
variations in drought resistance among the 5 St.
Augustine grass cultivars. Floralawn and Floratam
showed high green shoot recovery. They showed less
than 50% leaf firing after 34 days of drought stress
and recoveries of over 90%. However, Texas Common
and Raleigh St. Augustine grass as well as Prairie
Buffalograss showed over 98% leaf firing and less
than 20% recovery. The performance of Floratam and
Floralawn was excellent throughout the study in
terms of shoot color, turgidity, and uniformity.
They were comparable to 609 Buffalo grass.
Time will tell whether
tolerance) and Floratam (shade tolerance).