Reduced inputs at the Clinton Presidential Center

Maintaining highly attractive grounds at the William J. Clinton Presidential Center in Little Rock Ark., is essential. In addition to its historical focus, the site serves as a learning center for green operations and is a prime example of interagency cooperation.

The green roof helps with stormwater management.
Photos courtesy of Clinton Foundation, unless otherwise noted.
A small bentgrass putting green adds interest to the green roof.
Mowing begins in early spring.
Photo courtesy of The Good Earth.

The 30-acre site on the bank of the Arkansas River is on land leased from the city of Little Rock and it opened in 1994. While the presidential library system is operated by the National Archives and houses presidential historical documents, the libraries are built with private donations. The Clinton Presidential Center is also a city park and hosts the University of Arkansas School of Public Service. With the various aspects involved at the center, operations require cooperation among the private and public entities of the Clinton Foundation, National Archives, the city of Little Rock and the University of Arkansas.

In addition to the thousands of visitors to the center, including a large number of school groups and various other groups and organizations, special festivals and other activities are held at the site, creating heavy foot traffic on the lawn areas.

Regional accents

“First of all, the site has to look good,” said Debbie Shock, director of operations and facilities. Beyond aesthetics, the site focus is on carrying out a goal of the Clinton Foundation in presenting a learning center accessible to the public. The Clinton Presidential Center is a resource not only in the political arena, but also in environmentally friendly grounds management. During construction of the center, Shock came to Little Rock with Hensel Phelps Construction Company, and stayed on with the Clinton Foundation after the project was completed.

The center is as essentially southern as the former president whose name it bears. The landscape design represents the various land regions of the state of Arkansas, and the lawns were sodded with Arkansas-produced, warm-season zoysiagrass from Quail Valley Grasses in Little Rock.

The site was a former brownfield where trains had been serviced, and an extensive amount of contaminated soil had to be removed before construction could begin. “Semi-loads of soil were brought in from about 5 miles away,” Shock said. In addition to the local clay-type soil, some of the soil was from areas where the Arkansas River regular flooded, leaving a Delta-type soil. Layering soil interspersed with compacting filled in the large cavity created by the removal of soil.

The landscape design theme includes trees that grow in the various land regions. The regions represented start with northwest Arkansas and include hardwood trees such as sugar maple and northern red oak, followed by central Arkansas representations in holly and black gum trees. The Delta area includes sandbar willow trees, and an area with magnolia trees is designated the Contemplative Garden. The site encompasses land right up to the banks of the Arkansas River, and some of the native trees growing close to the river were kept as part of the park. Liorope, also known as monkey grass, is used extensively as ground cover. All flower beds and trees are mulched with hardwood mulch from local mills.

Reducing inputs

“We have a Platinum rating from the U.S. Green Buildings Association,” Shock said. She and Gregg Curtis of The Good Earth, the grounds management firm contracted to care for the grounds, credit the products added through the irrigation system with reducing the need for inputs of both water and nutrients. Those reductions are major considerations both for environmental concerns and for cost containment. Shock works closely with Curtis in grounds management decisions for the center.

Grounds management at the 30-acre Clinton Presidential Center represents interagency cooperation.
Debbie Shock and Gregg Curtis discuss spring turfgrass treatment.
Photo courtesy of The Good Earth.

The Good Earth was established in 1974 and purchased by Curtis and his wife Julie in 1997. The firm provides grounds management throughout Little Rock and has a dedicated crew for the center.

The Clinton Presidential Center was certified by the USGBA at the time of construction. An application can be made for grounds management ratings after two years, and Shock was eager to attain higher ratings. Points are awarded for various environmentally sound construction elements and grounds management practices, including stormwater management and reduced water and nutrient applications.

Shock said, “I wanted to get to that next level. We’ve cut our water and our fertilizer in about half by using the organic products.” Primarily, DeltAg and Roots products are used to assure the zoysiagrass retains the color and health desired while keeping with an environmentally sound management program. A Dosmatic injector is used to add liquid products to the irrigation system for precise measurements and mixes.

The site is fully irrigated using a Rain Bird Maxicom irrigation system, which has six controllers with 25 stations per controller. The irrigation source is the city water supply, and both 4 and 6-inch irrigation mains are used.

Maintaining the grounds

To fight compaction from the heavy foot traffic throughout the lawns, aeration is done each spring. Curtis said, “We use a Bluebird walk-behind aerator with a 2.5-inch tine, and it takes about a week to aerate the entire grounds.”

Mowing begins in the spring at a height of about 1.5 inches. “We’ll be up to about 3 inches by summer. There’s less damage to the turf at 3-inch heights. We apply very little nitrogen to avoid the fast top growth,” Curtis said. Mowers used at the center include a Walker bagging mower and a John Deere mulching mower with a 60-inch front deck.

Treatments to the turfgrass begin in April when Plant Power from DeltAg and Turf Vigor from Roots are applied with second applications in June if needed. Sulfur Plus from DeltAg and Thatch-less from Roots are applied in June when needed, and DeltAg’s Iron Plus is applied in July.

“Our pH went alkaline on us a few years after the center opened,” Shock said. “Apparently, some of the soil brought into the site had a high alkaline level that worked its way to the top.” Turf yellowing was observed, and following identification of the high alkaline soil levels, Sulfur Plus was used; it corrected the pH level and eliminated the turf yellowing. It is applied each June if soil tests indicate an alkaline level that needs to be corrected.

Green roof

Shock is particularly proud of the 4,000-square-foot green roof added in 2007. Green roofs have gained in popularity in recent years in helping to control stormwater runoff with the added benefit of reducing energy costs. While more prevalent in Europe, green roof research and installation is increasing in the U.S. for stormwater control and a reduction in heating and cooling costs. Shock said, “President Clinton has been very involved in the center. He saw green roofs in Chicago and wanted one here at the center.”

In addition to plants commonly recommended for the shallow growing settings of green roofs, the roof at the center include some special plants. Shock said, “We have yellow rose plants and blueberry bushes growing there. We’re eager to share what we grow with our visitors. Our blueberries are served in the on-site restaurant, Forty-Two, where our visitors can enjoy them.” A small bentgrass putting green is included on the green roof.

Green roofs, careful lawn management and ongoing cooperation are major elements in effective grounds management at the large site.

Nancy Riggs is a freelance writer and has been covering the green industry for Turf for almost 20 years. She resides in Mt. Zion, Ill.