Big-roll sod installation is underway at the Oakland Coliseum.
PHOTO COURTESY OF WEST COAST TURF.
It's all about the grass. While field aesthetics are the thrill factor, it's ultimately the safety and playability of the turfgrass surface that affects how the game is played. Turfgrass breeders, university turfgrass researchers and sod producers have joined forces with sports field managers to find answers specific to the unique needs of this highly specialized market. Several sod producers gave us an update on the turfgrass cultivars they are growing for sports fields and what factors led to that decision.
Reviewing the criterion
Variety selection must consider the general weather-related guidelines of the region, site-specific conditions, the level of maintenance and all anticipated usage. Results of the National Turfgrass Evaluation Program (NTEP, www.ntep.org) are a major part of the equation.
"In the transition zone, no one grass is the perfect answer," says Jim McHenry, sales manager of Oakwood Sod Farm, Delmar, Md. "We grow both warm-season and cool-season turfgrasses, with our primary selections for the sports field market Patriot bermudagrass and a blend of bluegrasses: Midnight, Beyond and Touche."
Big-roll sod harvest is underway at Oakwood Sod Farm in Delmar, Md.
PHOTO COURTESY OF OAKWOOD SOD FARM.
Sod producers develop their own systems for evaluating turfgrass cultivars. "We always follow the NTEP trials," says McHenry. "Currently, a couple of the new bermudas out of Oklahoma State look promising. We're also tracking some zoysia grasses from Texas A&M, though, because they're a bit slower growing, they may not recoup well enough from the wear of a college or pro-level field."
Graff's Turf Farms, Inc., Fort Morgan, Colo., focuses on cool-season grasses, primarily the bluegrasses, though co-owner Marty Thiel notes they are testing "a handful of bermuda cultivars" for future consideration.
Thiel says, "It's the genetics that make the end results in a turfgrass cultivar, and we need to pick the best. It's becoming harder to assess with so many new bluegrass varieties being introduced. We spend a solid month in the winter considering all the cultivars. We'll talk to half a dozen to a dozen seed companies, review what they have to offer, and select the best from several different suppliers to come up with the combinations we'll grow."
Consistency is important. It takes a minimum of 12 months to grow a crop of sod. Thiel says, "Suppliers can develop an excellent cultivar in performance ratings, but if it's not a good seed producer, it won't provide the volume needed to supply needs or generate the revenue they need to continue with it. We maintain contact with the owners of the seed to get their feedback on how long a seed will be in production and the anticipated level of availability."
Some of the older, proven cultivars may be dropped by seed producers to devote resources to newer introductions. That affects sod production, too. Thiel says, "We still use P105 as one of our staples, for its dark green color, cold tolerance and good wear tolerance. But it's not a strong seed producer, so it can be hard to get. We still use some North Star, too."
McHenry says, "When selecting our cool-season cultivars, we sought recommendations from the University of Maryland and Virginia Tech for the best low-mow performers, and we gathered feedback from sports field managers. Midnight, Beyond and Touche were top recommendations from both sources and they've performed very well, especially for those concentrating on spring and fall sports."
The increase in available cultivars also has affected the market. Thiel says, "Just five years ago, the majority of our sod production for sports fields was one basic blend of bluegrass cultivars. Now we're doing more custom growing, producing different blends for specific fields. We get their input on site microclimates, what they want in performance for their specific usage, and the parameters of their turf management program. If they have specific cultivars they've been following, we'll provide our input on what we've seen in performance from those and others with similar attributes to jointly determine the blend. In some cases, the sports field manager has worked through this process and has the specs already established."
Each cultivar plays a key role in the blend. Thiel says, "In our bluegrass blends, we try to include varieties from three of the Elite Turf Type subgroups, the Compact Type, Compact-Midnight Type and Compact-America Type. The strengths characteristic to at least one of the varieties should provide balance to any weaknesses in the others."
The top performance considerations for sod producers mirror those of sports field managers. For Graff's, wear tolerance is the most important issue, followed by disease resistance, early spring green-up and late fall color. Thiel says, "We rely heavily on feedback from the researchers from the cool-season region turf programs, like Penn State, Rutgers and Michigan State. A traffic study at MSU, now into the second year, is showing some varieties as great performers."
Wayne Thorson is president of Todd Valley Farms in Mead, Neb., a licensed grower of rhizomatous tall fescue (RTF). "It's an advanced generation of turf-type tall fescue that produces rhizomes," says Thorson. "That growth habit gives it the ability to form a tightly knit sod as a single cultivar. Our first installation was for a soccer field at a Millard, Neb., elementary school. We now have several installations at the University of Nebraska at Omaha, including four practice fields. We installed eight fields for a Bellevue soccer club, a multi-field soccer complex in Gretna, and the practice field for the Iowa State University marching band.
"We're seeing the same basic green-up schedule as bluegrass fields in the spring, with better holding power during the summer heat, even when irrigation is limited, because of the deep rooting. In some situations, it stays greener longer into the fall, but that depends on the site-specific environmental conditions. We're recommending it for multisport fields, especially those in heavy-use situations."
Cold-hardy bermudas like Patriot are becoming better accepted, according to McHenry. He says, "In Oakwood Turf Farm's local area, Virginia Tech, the University of Maryland and George Mason University are all using Patriot. It's strong in the summer, so it can handle the heavy use of camps or concerts. George Mason overseeds their soccer and baseball fields with perennial ryegrass for active growth in the late fall and early spring seasons."
Once established, the bermuda requires less input in fertilization, pest control and water. McHenry says, "Many of the high schools have gone the Patriot route and more are considering it because of that. Patriot often stays actively growing here into mid to late fall and holds its color fairly well into November, long enough to support their typical fall sports activity without overseeding. Those with spring sports generally overseed with a rye blend after the fall season and use a growth cover to encourage the rye. They'll transition out after spring sports and push the bermuda so it's ready by mid-August."
Turfgrass is a specialized crop grown for harvest.
PHOTO COURTESY OF WEST COAST TURF.
For West Coast Turf, with multiple growing fields in California and Arizona, the primary warm-season turf production is bermuda-grass, though they are growing some of the Seashore paspalums. Bluegrasses are highly susceptible to disease in southern California. They do grow some perennial ryegrass sod, using straight Chaparral for its good heat and salt tolerance and very good traffic tolerance.
John Marman, West Coast Turf regional sales manager, says, "Tifway 419 set the standard for bermudas and many sports field managers opt to stick with it. Dodgers Stadium, Angel Stadium and the new Diamondbacks/Rockies spring training facility in Arizona are all Tifway 419 fields."
Other sports field managers explore the new introductions, working through a variety of cultivars to find the performance they're after. Marman says, "Clay Wood, head groundskeeper for the Oakland A's, is finding better success with Tifsport than anything else he's tried. It handles the variable northern California conditions and transitions well for him."
Tifway II is the cultivar choice for the Rose Bowl and Candlestick Park. Grant Trenbeath, head groundskeeper for the Arizona Diamondbacks at Chase Field, is now using Bull's-Eye bermuda. Marman says, "It has a good blue-green color, is extremely tough and produces a dense canopy, but the primary attribute for Grant is its ability to handle the shade caused by the stadium configuration and the retractable roof."
A new cultivar for West Coast Turf production is Bandera bermudagrass, from Champion Turf Farms in Texas. Marman says, "It's very aggressive, actually the fastest crop that we've ever grown in at our sod farm. It holds color well, has a nice texture and good density. We've installed it on the Lake Elsinore Storm baseball field and at the Home Depot Center on practice field number one. Only the Home Depot Center field was overseeded so, at this point [mid-April], we haven't seen how it handles the transition out of the rye in our area."
West Coast Turf is also growing Dr. Ronnie Duncan's latest release. Platinum TE seashore paspalum. Marman says, "Dan Bergstrom, head groundskeeper for the Houston Astros, deals with coastal weather conditions that change like a roller coaster ride. He's having great success with it."
Pushing the window
The Oakland A's field is the farthest north West Coast Turf pushes the bermudagrasses in California. Marman says, "We've sent bermudagrass to Qwest Field in Seattle for high-profile soccer games. It's usually overseeded bermuda. When the sod is taken up from there it's donated to a local high school and several are now using it with great results."
When it comes to pushing cool-season varieties south, Marman says, "The limits we've seen in California are the Rancho Cucamonga Quakes and the Inland Empire 66ers in San Bernardino. Both are minor league baseball teams, with 100 percent ryegrass fields in city-owned and managed facilities."
Sod installation is underway for the Jacksonville Jaguars' field.
PHOTO COURTESY OF WEST COAST TURF.
Tap the resources
Each turfgrass cultivar has its own set of characteristics that separates it from all the others. Marman says, "The attributes of a specific cultivar may be enough to overcome a site-related situation that makes other cultivars struggle. Consult with your local turfgrass extension specialist, and with sod producers and other sports field managers about cultivar performance in the various soil types with differing water quality and availability, and in specific microclimates and light conditions, including stadium configuration shade issues or seasonal overcast situations. There may be different options that could provide a better playing surface - and that's what turfgrass variety selection is all about."
The author is a contributing editor for SportsField Management.