CHARACTERISTIC OF TURFGRASSES
Ch. 12, pp. 2 - 5
Characteristic: warm season | cool season
WARM SEASON GRASSES
Warm season grass lawns are actively growing from mid-April to
mid-October. They are termed "warm season" grasses
because they grow during warm weather. Most produce stolons and/or
rhizomes. Stolons are above ground runners, while rhizomes are
under ground runners. Both are stems that help produce plants and
help warm season grasses fill in areas and recuperate after stress
Bermuda grasses, (Cynodon spp.), have
two general categories common and hybrid. Common bermuda has leaf
blades which are 1/8" (3mm) wide, and attach themselves to
the grass shoot at intervals of about 1/4" (6mm). This leaf
width and leaf arrangement give common bermuda a "medium"
texture appearance. Common bermudagrass is best mowed between 1
1/2 --2 1/4" with a rotary mower. Common bermudagrass is
easily established from seed. Hybrid bermudagrasses are the result
of mating common bermudagrass with African bermudagrass. The
result is a plant which has fine leaf texture and does not produce
pollen or seed. Certain hybrid bermudagrasses have narrow leaf
blades (1/16") (2mm or less) and are attached very closely to
each other on the main shoot. They also have more individual
shoots per square inch of turf than common bermudagrass. Because
of the dense growth habit, hybrid bermudagrasses tolerate and
require shorter mowing heights. Tifgreen (Tif 328) can be mowed at
1/4" or less with special maintenance practices. Most hybrid
bermudagrasses are adapted to mowing heights of 1/2-1 1/4"
with a reel mower. Higher mowing heights of 1 1/2 -- 2" with
a rotary mower can result in puffy turf which is subject to
scalping. The hybrid variety E-Z Turf (Midiron) appears more like
common bermudagrass than the other Tifgreen hybrids. It is easily
mowed with a rotary mower, and does not scalp from puffiness which
occurs at higher mowing heights. Hybrid bermudagrasses are
established from vegetative plant parts and not from seed. It is
commonly established through sodding, stolonizing, and to a lesser
extent plugging. For more information, see Extension Bulletin No.
8752, Hybrid Bermuda Lawns.
Newly developed seeded bermudagrasses are becoming
increasingly available on the commercial market. Since they
produce seed, they must produce pollen. Newly released seeded
bermudagrasses with are being sold as improved turf types.
Some are substantial improvements over "Arizona
Common", some are not much different. Some of the advertised
darker green color
lower growth habit and subsequently shorter mowing heights
improved drought tolerance
less seed head production
The first generation of "improved turf-type seeded
bermuda grass" include the following cultivars:
Numex Sahara (NMSU)
Other varieties released include:
Many others are being tested for potential release.
Some of these are included in the germplasm tests at the Desert
Turf Center in Tucson. Others are "extra" proprietary
and are not regularly tested by universities. Therefore, there is
very little data to support claims or adaptation to Arizona. Major
breeding programs include experiments for evaluating mowing height
and fertility interactions of some of this new germplasm. Until
further notice, treat the seeded types as you would "AZ-Common".
There are tests underway in Oklahoma to evaluate cold
hardiness of bermudagrass, in order to increase its range of use.
The cultivar "Midron" (sold as E-Z Turf), Mirage and "Guymon"
have good cold tolerance. These two go dormant earlier in the
fall, and store more food reserves. "Midiron" does NOT
produce seed, it is a sterile variety which produces no pollen. "Guymon"
is a wide leaf blade seeded types, but it has short internodes. It
is very unique in this characteristic. "Guymon" will
produce pollen and seed. Bermudagrass should be established at a
rate of 1.0 to 1.5 lbs. of seed per thousand square feet. The last
type of bermudagrass is a "seeded-hybrid." This is a
special case. The variety "Princess," or the Princess "brand"
and related proprietory commercial brands of seed are lawn-type
bermudagrasses which are termed hybrids. This is because of the
special arrangement of seed plants in the production field. In
this sense, it qualifies as a "seeded hybrid." It does
however, make pollen and seed, if allowed to, in a mowed lawn.
St. Augustine, (Stenotaphrum secundatum)
grass has stolons but no rhizomes. Stems are flattened, with wide,
dull green leaves that lay flat on the ground. St. Augustine does
better in the shade than both bermuda and zoysiagrass. St.
Augustine grass is established by either sod, plugs, or
occasionally by seed. It produces a thick thatch over time and is
slow to grow back from a severe verticutting. It does not take to
overseeding. Like bermudagrass, it does go dormant (turns brown)
during the winter months when it is cold. It has a limited use in
our state for low elevation lawns which receive moderate shade
conditions where a brown winter turf is acceptable. Newer
varieties are currently under university testing.
Zoysiagrass, (Zoysia species), is slow
to establish when compared to bermuda grass but is more tolerant
of shade. Zoysia grass has both stolons and rhizomes. Leaf-blades
are borne at right angles to the stalk. Ligules have short dense
hairs. There are several species of Zoysia japonica, which is
common Japanese lawn grass. It is shade tolerant, but not as much
as St. Augustine. It is quite slow to establish, especially from
plugs. It is best established in June by either sod, or seeding,
if seeds are available. The seeding rate is 2.0--2.5 lbs. per 1000
square feet. Zoysiagrass seed contains dormant seed that will not
germinate right away. Ask for "dormant treated seed" if
you must have zoysiagrass. This seed is treated with an additive
or receives a cold (chilling) treatment which overcomes the
dormancy of the seed. Although it has both rhizomes and stolons,
zoysiagrass is slow growing, especially when compared to
bermudagrasses. Like St. Augustine, it does not tolerate
overseeding with ryegrass. However, it usually does retain its
green color longer in the fall than most bermudagrasses. Common
Japanese lawn grass can be mowed with a sharp reel mower at 1.25
inches, or with a rotary mower at 1.5 to 2.0 inches. Zoysiagrass
will become thatchy and puffy with time. When a verticutting is
called for, it is best done in early June followed by a
fertilization with a complete fertilizer (N--P--K). Zoysiagrass
use has diminished rapidly. Sod types are generally not available
Buffalograss, (Buchloe dactyloides) has
become popular in the trade literature. Buffalo grass is a native
grass which occurs as different land races from southern Mexico to
North Dakota. It is a warm season grass and is more closely
related to bermuda grass than cool season grasses. Here in
Arizona, its asset is that it can go 2 weeks without water at
higher elevations, if good soil moisture conditions allow it. In
the early and mid 1980s, Texas A & M and the University of
Nebraska began collecting and breeding Buffalo grass for turf.
Buffalo grass has male and female plants (dioecious), with
occasional and rare plants having both sexes. Seed from the female
is expensive because the seed capsules (burrs, which contain 2-3
seeds each) are low to the ground and require careful harvest and
The seeded types (which result in a mixed population of
male and female plants) available on the market for general
utility turfs area as follows:
"Texoka" released around 1960 by Dr.
"Sharp's Improved". Mid 1960s.
"Bison" Released in 1991 by Oklahoma State
"Tatanka" in 1996 by FMK
"Cody" in 1996 by FMK
All five of these cultivars can be used as forage or
low maintenance turfs.
It turns out that female plants on average have better
turf quality attributes than males (darker color, shorter
internodes, higher stolon densities, etc.). As a result,
Universities and sod companies have released single female clone
varieties for turf. Those available in Arizona that are sold as
"Prairie" Buffalo grass
"NE 609" Buffalo grass
NE 609 is the lower growing and darker green of the
two. A new release from Nebraska is NE 315, which is also darker
Buffalo grass has the following general traits:
Likes the warm weather (dormant in the winter
below 3000 feet and dormant in the fall at higher elevations).
Has a low water use rate.
If it runs out of water in the summer, it will enter
drought induced dormancy. That is, it will turn brown, just as it
does in the winter. If observed side by side with bermuda grass,
the Buffalo grass takes longer to wilt and holds it's color
longer. However, when irrigation is applied after stress, the
Buffalo grass takes longer to recover than bermuda grass. The more
repeated cycles of stress, the slower the Buffalo grass will be in
recovering. This is more critical for turfs used at low elevation
(3000 feet and below).
At low desert elevation, it looks like there is no real
advantage to Buffalo grass over bermuda grass in water use.
Mowing height is 2.0 inches (as the preferred base
height). Mow with a rotary mower. Raise to 2.5 or 3.0 inches in
poor soils and/or minimal irrigation.
Buffalo grass has a lower nitrogen requirement than
bermuda grass. You can slow the grass down and actually weaken it
with too much fertility. It needs maybe 1.0 lbs -N-/1000 ft2/year,
preferably in split applications of 1/2 lb. in June and July or
August (May is a possible substitution for June, also). If in a
non-irrigated situation, apply the fertilizer in the middle of the
Since it has a lower growth rate than bermuda grass, its
recuperative capacity is less. Therefore, the current Buffalo
grass varieties are not recommended for use in high traffic
situations, as they would not grow back fast enough during
constant use. At higher elevations, Buffalo grass may be more
adaptable at 3,500 feet and above. Mow it at 2.5 inches as the
base height if it gets standard turf maintenance.
Shade: The commercially available germplasm is not shade
tolerant. There are some types from Mexico that are more shade
Buffalo grass is not salt tolerant. There are genotypic
differences, but its a far cry from bermuda grass salt tolerance.
Plant seed in June! Don't wait till July. The sooner the
better. If you have only the monsoon to water, you must plant
during that time. Seed at 1.0 - 1.5 lbs of pure live seed per 1000
ft2. Check the label to see how much seed is dormant
the first year. Some seed may be pretreated to eliminate dormancy.
If using sod (Prairie, NE 609, etc.) plant the sod in June as the
first choice. You can also plug. The plugs and sod will loose
color after transplanting, even under proper watering. They will
start to green up after two weeks and then stolons (they have no
rhizomes), will be produced.