Richard L. Duble, Turfgrass Specialist Texas Cooperative Extension Text and Images Copyright

Bermudagrass

Bermudagrass (Cynodon spp.) is a major turf species for sports fields, lawns, parks, golf courses, and general utility turfs in Australia, Africa, India, South America and the Southern region of the United States. It is found in over 100 counties throughout the tropical and subtropical areas of the world. Common bermudagrass, C. dactylon, naturalized throughout the warmer regions of the United States, was introduced into this country during the colonial period from Africa or India. The earliest introductions are not recorded, but bermudagrass is listed as one of the principal grasses in the Southern States in Mease's Geological Account of the United States published in 1807.
The genus Cynodon comprises nine species with C. dactylon being the most widespread. That C. dactylon is a tetraploid with broad genetic variability serves to explain its widespread distribution. Other Cynodon species have a more limited natural distribution and are often restricted to one particular habitat. C. dactylon is highly fertile, whereas the diploid species such as C. transvaalensis rarely produce viable seed.
C. dactylon (L.) Pers is commonly called bermudagrass in many areas of the world. But, it is also known by numerous other names including "Kweekgras" (S. Africa), couch grass (Australia and Africa), devil's grass (India) and gramillia (Argentina). The variety of names given this species attests to its wide distribution and to the fact that it is the object of abuse and scorn.
In addition to being a widely used species for forage and turf, C. dactylon is a serious weed in many crops. Being a vigorous, stoloniferous grass, it rapidly invades crops in high rainfall or irrigated areas. C. dactylon is ranked among the three most troublesome weeds in sugarcane, cotton, corn and vineyards in many countries. It is a difficult weed to eradicate because of its seed production and deep rhizomes.
In the United States the distribution of bermudagrass extends from New Jersey and Maryland southward to Florida and westward to Kansas and Texas. Under irrigation its distribution extends westward to southern New Mexico, Arizona and to most major valleys in California. The development of more cold tolerant turf-type varieties of bermudagrass such as U-3 and Midiron has increased interest in the species near its northern limits. Low winter temperature is the factor that limits the northward distribution of bermudagrass.

Description. Bermudagrass (C. dactylon (L.) Pers.) is a highly variable, sod forming perennial that spreads by stolons, rhizomes and seed. Stolons of bermudagrass readily root at the nodes. Lateral buds develop at the nodes to produce erect or ascending stems that reach 5 to 40 cm (rarely over 90 cm) in height. In most Cynodon sp., leaves are borne on stems with long internodes alternating with one or more very short internodes. This characteristic gives the impression that the species has multiple-leaved nodes. Leaf sheaths are compressed to round, loose, split, smooth, sparsely hairy, up to 15 cm long, and with a tuft of hairs 2 to 5 mm long. Auricles are absent. Collar is continuous, narrow, glabrous and hairy on margins. Leaf blades are 2 to 16 cm long, 1.5 to 5 mm wide, smooth to sparsely pubescent, folded or loosely rolled in the bud and sharply-pointed. The inflorescence consists of 3 to 7 spikes in a single whorl in a fingerlike arrangement and 3 to 10 cm long. In robust forms there may be up to 10 spikes, sometimes in two whorls. Spikelets are 2 to 3 mm long, in 2 rows tightly appressed to one side of the rachis; glumes are to ° the length of spikelet; lemma is boot-shaped, acute with fringe of hairs on the keel and longer than the glume; seed is 1.5 mm long, oval, straw to red-colored and free within the lemma and palea.
Bermudagrass has a fibrous, perennial root system with vigorous, deep rhizomes. Roots are produced at the nodes after new leaves or tillers are produced during the growing season and after new shoots are produced in the spring. Mature roots are yellow to brown while new roots are white. Mature roots deteriorate throughout the growing season and new roots are produced continuously. Root production and dieback has been reported to be particularly high in the spring at the onset of shoot production.
Adaptation and Use. Bermudagrass is a warm season perennial species adapted to tropical and subtropical climates. It grows best under extended periods of high temperatures, mild winters and moderate to high rainfall. Temperature is the main environmental factor that limits its adaptability to tropical and subtropical areas of the world. The northern limits of bermudagrass extend into the transitional zone of the United States where low temperatures seldom drop below 10°F. In general, temperatures below 30°F kill the leaves and stems of bermudagrass. Research has demonstrated that bermudagrass will continue to grow with night temperatures as low as 34°F if day temperatures are near 70°F. However, when average temperatures drop below 50°F growth stops and the grass begins to discolor. At the onset of low temperatures in the fall and winter, bermudagrass begins to discolor, protein fractions change in composition and reserve carbohydrates increase in the stems and rhizomes. After the first killing frost, leaves and stems of bermudagrass remain dormant until average daily temperatures rise above 50°F for several days. The roots and rhizomes of bermudagrass continue to grow several weeks after the leaves and stems stop growth.
In warm frost-free climates bermudagrass remains green throughout the year, but growth is significantly reduced at the onset of cool nights. The species makes the best growth where average daily temperatures are above 75°F. Optimum daytime temperature for bermudagrass is between 95° and 100°F.
Soil temperature, as influenced by air temperature, is also important to the growth and development of bermudagrass turf. Soil temperatures above 65°F are required for significant growth of rhizomes, roots and stolons. Optimum soil temperature for root growth is around 80°F.
Bermudagrass has a high light requirement and does not grow well under low light (shaded) conditions. The duration of the light period (day length) also influences growth and development of bermudagrass. Both increased light intensity and day length increase rhizome, stolon and leaf growth in bermudagrass. At low light intensities (less than 60% full sunlight) bermudagrass develops narrow, elongated leaves; thin upright stems; elongated internodes and weak rhizomes. Consequently, bermudagrass develops a very sparse turf under moderately shaded conditions.
Bermudagrass is found in tropical and subtropical climates with 25 to 100 inches of annual rainfall, but it also survives in arid climates along waterways and in irrigated areas. Where annual rainfall is below 20 inches per year, bermudagrass requires irrigation to survive. Bermudagrass develops into a semidormant state during very dry conditions, but has the capability of surviving extreme droughts. Rhizomes of bermudagrass can lose 50% or more of their weight and still recover when favorable moisture develops. Generally, common bermudagrass, or tetraploids of C. dactylon, have the deepest root and rhizome penetration and better withstand prolonged drought periods.
Common bermudagrass also has the characteristic of producing seedheads under stress conditions such as drought. Thus, the seeds provide another method by which the species can survive extreme drought. Some natural biotypes of C. dactylon produce numerous seeds. The seeds are very small with about 2,000,000 seeds per pound.
Bermudagrass grows well on a wide variety of soils from heavy clays to deep sands, provided fertility is not limiting. It tolerates both acid and alkaline soil conditions and is highly tolerant to saline conditions. Bermudagrass survives some flooding but does best on well-drained sites. Although it may persist under low fertility, bermudagrass has a high nitrogen requirement for good quality turf.
Bermudagrass has numerous turf uses. It has been suggested that if ever a plant deserved a monument for its service to mankind, it was bermudagrass for what it has done to prevent soil erosion, to stabilize ditch banks, roadsides and airfields, to beautify landscapes and to provide a smooth, resilient playing surface for sports fields and playgrounds. Bermudagrass also provides hay and pasture for livestock throughout the tropical and subtropical areas of the world.

Turf uses of common bermudagrass include sports fields, lawns, parks, playgrounds, golf course fairways, roadsides, cemeteries, and other general purpose turf. Hybrid bermudagrass and selections of common bermudagrass are used for special purposes such as sports fields, golf greens, bowling greens, tennis courts, and lawns.
Bermudagrass is well suited to high traffic areas such as sports fields, golf courses, and playgrounds. A dense bermudagrass turf tolerates moderate wear and compaction and recovers rapidly from wear injury. Under moderate fertilization, frequent mowing and adequate moisture bermudagrass forms a dense, fine-textured turf. The only situation where bermudagrass cannot be used is in moderate to heavily shaded sites.
Varieties. Selections of superior strains of common bermudagrass, natural hybrids between C. dactylon and C. transvaalensis and crosses resulting from grass breeding programs have been released by state universities, the Crop Research Division of the USDA and the U.S. Golf Association Green Section. All of the hybrid bermudagrasses are sterile and must be propagated by sprigs or sod. Some selections from C. dactylon produce viable seed. Nu-Mex Sahara and Princess bermudagrass are improved seeded varieties of bermudagrass. Brief descriptions of the major sports turf-type bermudagrass varieties follows:
U-3 (C. dactylon). Selected from Savannah Golf Club near Savannah, Georgia in 1936 from a series of fine-strain selections. Selected because of its cold hardiness, fine texture, rapid spread and durability under a wide range of soil and climatic conditions. The selection was released in 1957 by the Crops Research Division, ARS, USDA, and the U.S. Golf Association Green Section. Adapted for use on lawns, golf courses and athletic fields.
Sunturf (C. magennissii). Originated in S. Africa as a natural hybrid between C. dactylon and C. transvaalensis and introduced into the U.S. in 1949. Released cooperatively by Alabama, Arkansas, Oklahoma and South Carolina Agricultural Experiment Stations in 1956. Dark Green, fine-textured, low growing variety that forms a very dense turf. Widely used for lawns in the southwestern U.S.
Tiflawn (Cynodon sp.). A hybrid between two selections from a pasture breeding program at the Georgia Coastal Plains Experiment Station at Tifton. Released in 1952 by Georgia Agricultural Experiment Station and the Crops Research Division, ARS, USDA. A medium-textured, very fast spreading, wear resistant variety that forms a dense, weed-free turf. Particularly well-suited for lawns and athletic fields in the southeastern U.S.

Tifgreen (C. dactylon x C. transvaalensis). A hybrid between a fine- textured selection of C. dactylon from the Charlotte Country Club, Charlotte, North Carolina, and C. transvaalensis. Released in 1956 by Georgia Agricultural Experiment Station and Crop Research Division, ARS, USDA. Tifgreen in a low growing, rapid spreading variety that develops a dense, weed resistant turf. Its density, fine texture and soft leaves make Tifgreen an excellent turf for golf greens. Also, it tolerates overseeding with winter grasses better than most bermudagrass varieties. Tifgreen is highly susceptible to injury by ground pearls in the southwestern U.S. and is severely discolored by air pollution in areas where this is a problem. It is also highly susceptible to spring dead spot in the transition zone of the U.S. Tifgreen is recommended for golf greens and fairways, tennis courts, bowling greens and fine lawns with a high level of maintenance.
Texturf-10 (C. dactylon). Selected from common bermudagrass fairway at the Corsicana Country Club in Corsicana, Texas, for its medium texture, dark green color, sparse seedheads and dense turf. It also has good wear tolerance and late fall color retention and makes earlier spring recovery than common bermudagrass. Texturf-10 was released by the Texas Agricultural Experiment Station in 1957. It is recommended for athletic fields, playgrounds and lawns. Texturf-10 is sensitive to chlorinated hydrocarbon insecticides, turning a straw color several days after an application of these materials. The grass recovers in 7 to 10 days with no permanent damage.
Tifway (C. dactylon x C. transvaalensis). A chance hybrid that appeared in a lot of seed of C. transvaalensis from Johannesburg, South Africa, in 1954. It is very similar to Tifgreen except for its greater stiffness of leaf blades and darker green color. Released by the Georgia Agricultural Experiment Station and Crops Research Division, ARS, USDA, in 1960. Recommended for golf course tees and fairways, home lawns, athletic fields and tennis courts. An improved selection of Tifway, Tifway II, was recently released for its superior cold tolerance.
Santa Ana (C. dactylon x C. transvaalensis). A selection from C. dactylon (Royal Cape) obtained from South Africa in 1954. The initial selection was made at UCLA in 1956 for its deep blue-green color, medium-fine texture and good fall color retention. Santa Ana was found to have good salt tolerance and a high degree of tolerance to smog which frequently discolored Tifway and Tifgreen varieties. Released by the California Agricultural Experiment Station in 1966, Santa Ana is recommended for golf courses, athletic fields, playgrounds and lawns. Careful management is required to prevent thatch accumulation.
Ormond (C. dactylon). Selected from a fairway at Ellinor Village Country Club, Ormond Beach, Florida, for attractive blue-green color, vigor and prostrate growth habit. It has a medium texture and tolerance to leaf disease, but lacks cold tolerance. Released by Florida Agricultural Experiment Station in 1962. Well adapted in Florida for use on lawns, golf courses, playgrounds and athletic fields.
Midway (C. dactylon x C. transvaalensis). A medium-textured lawn grass that produces relatively few seedheads. Released by the Kansas Agricultural Experiment Station in 1965 for its superior cold tolerance in Kansas. Recommended for lawns, golf courses and athletic fields in the upper South.
Tifdwarf (C. dactylon x C. transvaalensis). A selection from Tifgreen golf greens in Sea Island, Georgia, and Florence, South Carolina, where both greens were planted with Tifgreen obtained from the Georgia Coastal Plain Experiment Station at Tifton. Evidence indicates that Tifdwarf is a vegetative mutant that occurred in Tifgreen at Tifton before the first planting stock was sent out for testing. Tifdwarf resembles Tifgreen except that its leaves and internodes are significantly shorter than those of Tifgreen and it has a darker green color. Tifdwarf turns a reddish-purple color after the first cool temperatures in the fall. High rates of nitrogen in the fall will reduce the degree of discoloration. Tifdwarf is slower to recover than Tifgreen when both are planted on 12-inch center. Released by the Georgia Agricultural Experiment Station, Tifton and Crop Research Division, ARS, USDA, in 1965 for its superior putting quality. Tifdwarf is recommended for golf greens, tennis courts and bowling greens.