GOLF COURSE CARE Dutch, who brought the grass from Kenya to South Looking Kindly Africa and Australia during the Boer War. Kikuyu- grass was eventually transported to other areas and is at Kikuyugrass now cultivated in many mild climates throughout the Green Section Record-July/August 2003 world, including South Africa, Australia, New Zealand, Mexico, Spain, Central America, South America, and portions of the United States. Long considered an invasive weed, this warm-season grass is managed by many Improvement of kikuyugrass began in the 1950s courses as a desirable turf species. when the Australian government awarded a grant to a plant breeder to develop a seeded forage type for live- By Patrick J. Gross stock. The rapid growth rate, palatability, and high Kikuyugrass is the Rodney Dangerfield of turf - it protein content made kikuyugrass an ideal forage for gets no respect. While many courses fought the inva- cattle and livestock. The breeder, Dr. Whittet, devel- sion and spread of kikuyugrass for decades, others oped the cultivar that bears his name and sold the first have learned to manage this grass to provide good 22 lb. batch of seed to the Eykamp family for com- playing quality on tees, fairways, and rough. Why the mercial seed production in New South Wales, Aus- change of heart? Some courses had no choice but to tralia, where the Whittet variety is still grown today. learn to manage their former enemy as it gradually spread over most of the course. Other courses did not The establishment of kikuyugrass in the United have the budget or resources to control infestations States occurred in 1918 when it was imported to Pa- with multiple herbicide sprays, physical removal, and cific Palisades, California, as an erosion control for sodding. As superintendents learned more about the ditch banks, and it gradually spread to the coast and grass, they were able to adapt management practices inland valley areas. Many golf course superintendents to provide a dense, uniform turf with good playing and homeowners misidentified the grass as St. Au- quality. Although much of the literature to this point gustinegrass due to the similarities in leaf blade has focused on the control of kikuyugrass, this article width, color, thick stolon, and dense canopy. From will look at the culture and management of kikuyu- California, the grass was transported and spread to grass as a fine turf for golf courses. several states, including Hawaii, Arizona, and Texas. History and Background Don Eykamp, son of the original grower, brought Kikuyugrass (Pennisetum clandestinum) is a warm- kikuyugrass seed to the United States in 1995 with the season grass that is native to the Kenyan highlands of intention of producing seed and improving the species Africa. It is a course-textured grass with a rapid for the American forage and turf market. The main growth rate, and it is commonly used as a forage grass stumbling block was that kikuyugrass was listed as a and turfgrass in mild coastal climates and sub-tropical noxious weed in most states due to concerns that it regions. The spread of kikuyugrass was aided by the might be a host for an insect or a fungus that could Continued on page 2 Looking Kindly at Kikuyugrass Continued from Page 1 devastate the United States millet crop. The host plant habit, and the thick, fleshy stolons. Kikuyugrass is relationship was disproved, but the federal govern- distinguished by the pointed leaf tip, flat leaf blade, ment continues to list kikuyugrass as a noxious weed, and the long fringe of hairs that parallels the stem citing that it has an invasive growth habit. The status near the leaf collar. In contrast, St. Augustinegrass has of kikuyugrass currently is under review, and a ruling sharply folded leaves and blunt leaf tips. Another dis- by the governing agency, APHIS, is expected in the tinguishing characteristic of kikuyugrass is the promi- coming year. nent anther and white filament that extends above the canopy on closely cut turf. The white filaments typi- In the meantime, seed produc- cally are visible in the spring tion of Whittet went forward in and fall, but they can be seen Arizona under special permit. throughout the year in some lo- During this time, further improve- cations. The white filaments re- ment in kikuyugrass occurred in turn within a day of mowing, the seed fields of Arizona as a re- giving the turf a silvery cast. sult of natural selection. A patch The female part of the flower is of kikuyugrass with a finer texture near the base of the plant, and and improved density was ob- the seed is formed within the served in a field of Whittet. The leaf sheath. The seeds are seed from the unusual patch was rounded and dark brown, ap- replanted, and the progeny dis- proximately 1/8" in length. played the same desirable charac- teristics, resulting in the new The growth rate of kikuyu- variety Arizona-1 (also called AZ- grass is very rapid under warm, 1). moist conditions. Shoot exten- sion can exceed 1" per day at Today, kikuyugrass is managed as the primary turf in the height of the growing season. Active growth oc- fairways and rough at several golf courses, including curs at temperatures between 60° to 90°F, and it can prominent PGA Tour stops Riviera Country Club, Tor- survive well at temperatures near 100°F. Kikuyugrass rey Pines Golf Course, and La Costa Resort and Spa. sustains active growth and retains color at tempera- tures below 60°F, when most other warm-season Kikuyugrass Characteristics grasses exhibit a loss of color and a slower growth Kikuyugrass has been described as "bermudagrass pattern. In California, kikuyugrass may not go dor- on steroids." It is a coarse- to medium-texture warm- mant during the winter along the coast, although it season grass with a rapid growth rate. The leaf width tends to enter dormancy from late November until ranges from 1/8" to 1/4", comparable to Japanese February in colder inland valley locations. Kikuyu- lawngrass (Zoysia japonica) and St. Augustinegrass grass appears to have the best winter color retention (Stenotaphrum secdundatum). The wider leaf blade is of all the warm-season grasses and can tolerate light typical of the native types, while the narrow leaf blade frost without a loss of color. is typical of improved varieties under intensive man- agement. The leaf blades are flat and pointed at the tip Kikuyugrass spreads by stolons, rhizomes, and and typically grow in length from 1" to 10". Leaf seed. The thick, fleshy stolon and relatively wide leaf color is a medium to lime-green that some golfers and blade contribute to a somewhat open growth habit at superintendents find objectionable. mowing heights above 11/2". Canopy density is sig- nificantly improved at mowing heights below 5/8". Kikuyugrass is often confused with St. Augustine- Rooting occurs at the nodes of stolons under moist grass due to similarities in texture, color, growth soil conditions. Rooting is significantly restricted in 2 Continued on page 3 Looking Kindly at Kikuyugrass Continued from Page 2 dry soil, causing the turf to become puffy and more Propagation and Establishment prone to mower scalping. The irony of kikuyugrass is that it spreads rapidly where it is unwanted, but it can be slow to establish in The rapid growth rate and thick mat layer associ- existing turf or when efforts are made to actively cul- ated with kikuyugrass contribute to excellent traffic tivate and spread it. Control efforts are usually aban- tolerance and recovery from divot injury. The rapid doned once kikuyugrass populations reach 30% to growth rate is both a benefit and a challenge for main- 40%. At this point, most superintendents begin active tenance. Excessive thatch contributes to spongy sur- programs to cultivate and spread kikuyugrass to en- face conditions, mower scalping, and diminished courage a uniform stand. quality. If left unmowed, kikuyugrass has been ob- served growing over fences, up utility poles, and into The primary methods of propagation are sod, plugs, trees and shrubs. Under routine mowing and mainte- sprigs, and seed. The most successful method of es- nance, it can invade greens and tees unless a routine tablishment is transferring sod to provide a solid turf edging and hand-picking program are in place to con- cover. Until recently, golf courses in the United States trol encroachment. Kikuyugrass provides good play- had to propagate their own sod in a nursery area, but ing conditions and ball support when closely mowed, commercially grown sod is now available in Southern but the heavy thatch layer tends to limit ball roll on California at a cost of approximately 85¢ to $1.00 per fairways and provides unpredictable bounces on the square foot. putting green approach. It can be especially treacher- ous in the rough, where the thick stolons and wide Some courses have attempted to establish plugs of leaf blades tend to grab the club and make it difficult kikuyugrass in existing stands of bermudagrass using to extract the ball. a specially modified aerifier that removes 2" to 3" di- ameter cores for transplanting. The plugs can be slow Kikuyugrass tolerates a wide range of soil condi- to establish even if planted in the fall when bermuda- tions. Optimum growth seems to occur in medium- to grass is less competitive. Plugs planted on 12" centers heavy-texture soils with a neutral to alkaline pH. Like in the fall will provide reasonable coverage by the end many warm-season grasses, kikuyugrass has good tol- of the next growing season. erance to heat, drought, and salinity. It prefers ade- quate soil moisture but survives drought with a slight Sprigs collected following vertical mowing can be loss of color and a reduction in growth rate.