Two Courses in One

Golf courses in Arizona face a unique challenge compared to courses in cooler climates. Golfers demand superior conditions year round. Since no turf presently exists that can thrive in both hot and “cooler” weather, we overseed.

Overseeding:
Warm season grass varieties, typically bermudagrass, are chosen as the base turf for courses that overseed. In the winter, they don’t “die out” rather they simply go dormant losing its green color and its recuperative potential. Dormant bermudagrass can offer an acceptable playing surface but it does not have the same visual appeal as an overseeded course.

Cool season grass varieties, most typically perennial ryegrasses, do well in the winter. Ryegrass varieties are plentiful and suppliers are constantly developing new strains with improved characteristics such as color, texture, density, heat tolerance, drought tolerance, etc. It is seeded into or “over” the base bermudagrass to provide an enjoyable golfing experience for the winter months.

The Process:
Overseeding usually takes place anywhere from September to November. Step one consists of preparing the surface for the seed. A variety of practices are used such as growth regulators, drying down the existing turf, verticutting, scalping, etc. Step two is the application of seed. Seed rates vary depending on what is being seeded. Greens, tees, fairways and roughs all require different seed rates. Step three is irrigation to promote germination. This requires water to run on frequent, short cycles to keep the seed wet. Germination takes five to seven days after which the intensity of irrigation is reduced. Step four is the initial mowing and subsequent lowering of mowing heights until the preferred height is obtained. Further management of the overseeded areas consist of fertilization programs designed to promote maturity and a playing surface that will provide the expected playing conditions for the winter months.

After the ryegrass dies out the transition (anywhere from June to August) back to healthy, playable bermudagrass occurs. Following transition the turf manager has precious little time to enjoy quality bermudagrass for the remainder of the summer. There are seed orders to place, irrigation systems to troubleshoot and equipment to prepare for the next cycle of overseeding.

Article written by Mike Petty. Mike is the Director of Agronomy at the Omni Tucson National Resort and is responsible for the beauty of the Omni’s
two, 18-hole championship courses!