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Having it all
A Southern California venue tests a new approach to settle the dispute between advocates and opponents of overseeding.
Overseeding dormant bermudagrass for winter play almost always tops the list of hot-button issues in California golf course management. Since November 1999, Vista Valley Country Club’s superintendent, Ron Nolf, CGCS, and members at the Vista, Calif., layout have been developing procedures to reduce the negative aspects of overseeding and produce the best year-round turf quality with the least possible golfer interference or course closure.
Vista Valley CC is a private 18-hole course nestled in the native chaparral hill country of northern San Diego County. The equity-owned club, built over a three-year period from 1977 to 1980, was recently purchased by members John and Terri Havens, who also own the world-famous Cal-a-Vie health spa located adjacent to the 14th hole. Nolf arrived in 1979 from Pennsylvania to help make the Vista Valley golf course dream a reality.
A 50/50 controversy
Golfers also disliked the multiweek closures required each fall for overseeding and the $35,000-per-year cost. And they really hated being restricted to the paths for six to eight weeks while the course was heavily irrigated to establish the newly planted perennial ryegrass. Golfers venturing into the newly planted areas found their balls literally stuck in the mud during germination and establishment time each fall.
Nolf, a 35-year GCSAA member, found the members divided into several very vocal camps regarding overseeding. Snowbird members from northern states wanted green turf when they came to Southern California to spend winters and did not care about summer turf loss. Year-round resident members liked the green winter turf, but were becoming increasingly angry about the progressive bermudagrass turf loss seen each summer. A small contingent of members realized overseeding was gradually destroying the bermudagrass base and ultimately reducing year-round play quality.
During this time, a membership vote was taken to see if overseeding should continue. The vote was a dead heat, exactly 50 percent for and 50 percent against. Nolf continued to find himself in the middle of the overseeding controversy.
Looking for overseeding alternatives
Nolf returned from Orlando with ideas that could improve year-round golf course quality and also reduce course closure time. Discussions with each of the groups for and against overseeding took time and patience. After extensive discussions with golfers and club leaders, Nolf developed a multiyear action plan to reverse the downward trend seen on the course, including:
• Planting improved common bermudagrass to establish a solid base of turf
Nolf added selective chemical removal of perennial ryegrass and kikuyugrass from the bermudagrass during the fourth (overseeding) year in spring and summer. The chemical ryegrass removal procedure speeds up bermudagrass transition by removing weed grass competition and ensuring a minimum of 100 days of bermudagrass growth each summer for carbohydrate storage before the next overseeding.
Nolf noticed a dramatic difference between traditional overseeding (using vertical mowing, a slicer/seeder seed planting, course closure and heavy irrigation to germinate and grow-in the applied seed) and overseeding using the dry-spray seeder that did not require any seedbed preparation, course closure or extensive extra irrigation.
Implementing the plan
Some golfers were pleased to see the turf quality gradually improving as the procedures continued and the areas without turf were eliminated. Others remained skeptical. The controversy between advocates and opponents of overseeding ranged between a slow simmer to a full rolling boil during these course-improvement years. Half the membership threatened to quit if overseeding was not done and half did not want overseeding because of the cost and play restriction during “the best time of the year for golf.” Golfers also did not want a replay of the extensive turf loss seen in previous years from bermudagrass damage following overseeding.
In his quest to continue improving turf uniformity, Nolf began applying a herbicide (Drive, BASF) in 2001 to remove encroaching kikuyugrass from the bermudagrass. The improvement to the bermudagrass was dramatic after only 30 days.
In the fall of 2002, Nolf used the dry-spray seeder to overseed only the roughs at Vista Valley, leaving the fairways with non-overseeded dormant bermudagrass. To minimize traffic damage, golf cars were restricted to the fairways. The traffic experiment was a miserable failure, however, because golfers wore out the rough turf by driving in a line where the rough met the fairway edge.
Trial fairway overseeding was also done in four Vista Valley fairways and at Oak Creek Golf Club in Boulder City, Nev.; Seven Oaks in Bakersfield, Calif.; and Barona Creek GC in San Diego.
Additional new procedures at Vista Valley in 2003 produced more improvement. Nolf implemented a nine-hole closure rotation system to accommodate aeration, leaving the other nine holes open for play. The crew overseeded all fairways and tees, aerified and topdressed all of the greens, and built a 100-foot-long cement golf car path during a four-day period using these new procedures. The membership responded with appreciation.
• Traditional seeding methods using seedbed preparation including scalping and vertical mowing took five days for seed to germinate. Careful examination of the overseeded turf canopy showed the dry-spray seeding method also took five days for seed to germinate. The no-cultivation method will not remove bermudagrass. As a result, the germinating ryegrass becomes visible only when it grows taller than the existing bermudagrass, creating an illusion of a longer germination period. No course closure or seedbed preparation was needed. A lower mow was done just prior to planting.
• Newly planted seed must be irrigated during the day following dry-spray seeding to ensure acceptable germination and establishment. Since the seed germinates in the thatch of the existing turf instead of being exposed to the sun and air, the irrigation can be lighter. Course closure is not required, but golfers may be inconvenienced during increased irrigation periods.
• In common bermudagrass, the seed that is blasted from the dry-spray seeder can penetrate into the crown region. Seed applied to hybrid bermudagrass required a flex-tine harrow to open up the turf surface prior to planting to provide a place for the seed to land for germination. Overseeded perennial ryegrass bounced off the hybrid bermudagrass surface without light surface cultivation, reducing germination and establishment success.
• A plant growth regulator (Primo, Syngenta) application to suppress bermudagrass just prior to overseeding followed by a second application when the new ryegrass is visible provided the best overseed result.
• Frost exposure to newly planted turf resulted in a temporary decrease in turf density by causing the bermudagrass to go dormant. Overseeded turf density improved after several weeks as the newly planted perennial ryegrass became visible above the dormant bermudagrass and density increased with growth and establishment to produce a healthy green turf.
• Fairway turf had only minimal damage following dry-spray seeding because the seed is protected near the plant crown within the sod. Fairways with unlimited golf car traffic eventually showed the same turf density compared to fairways without traffic. Heavily trafficked turf took one to two months longer following planting to reach equivalent turf density compared to non-trafficked turf. In October 2004 and January 2005, traffic had to be restricted when rainfall saturated the soil. Unlimited traffic can resume once the course dries out.
• As a result of the overseeding successes, Vista Valley has been selling memberships during winter months for the first time.
• The dry-spray seeding program resulted in outstanding fairway turf density, no course closure during overseed periods and a 25 percent savings in seed application costs. Chemical removal of overseeded perennial ryegrass using a sulfonylurea herbicide (Revolver, Bayer Environmental Science) in late spring and early summer showed improved bermudagrass density as a result of a minimum 100 days of bermudagrass summer growth. Bermudagrass density also has improved following three summer herbicide applications to remove kikuyugrass. Application of these herbicides also eliminated crabgrass and swinecress encroachment.
Can golfers have both green winters with overseeded ryegrass and green summers with healthy bermudagrass? According to Nolf at Vista Valley, results since 1999 show with conscientious research, hard work and consistent communication, golfers can have it all.
Leo Feser Award candidate