Navigating Difficult Lawns
The right tools and techniques for the job
Very few lawns are simple to maintain – some are too big, some are too small, some are too steep, some have too many obstacles to go around, etc. Then there are the lawns that take these challenges to the extreme. For those properties, it takes a special approach – and sometimes special equipment – to get the job done.
In the mountainous terrain of North Carolina, for example, Butch Hamby with High Country Mechanical mows some lawns that exceed 30 percent in grade. “I started out in this business 10 years ago with two Murray riding mowers – that’s the honest truth,” Hamby recalls. It didn’t take him long to learn that he’d have to upgrade his equipment if he wanted to be successful, especially in an area where steep slopes are everywhere. In searching out the best tool for the terrain, he tried out a Ventrac. “I still have my original mower, and it has more than 8,000 hours on it,” he says.
Steep slopes can be difficult, or impossible, to mow safely without proper equipment. Ventrac produces mowers rated to mow on slopes up to 30 degrees, and when outfitted with finish mowing decks can produce a golf course-quality cut.
PHOTO COURTESY OF VENTRAC.
Hamby now has a fleet of five Ventracs, and while he acknowledges that the up-front capital investment is high, the units easily pay for themselves over time in durability and increased productivity. “We can put them on some sites and take a 1-hour-45-minute job down to 15 minutes,” he says.
One sloping lawn that Hamby maintains is .25-mile long and rises as high as 140 feet. “But the mowers handle it without any problem. You’re sitting about 6 inches off the ground, and the machine is 6 feet 1-inch wide – the center of gravity is just unbelievably low,” he explains. One 12-acre swath of common lawn he mows at a residential development is steeper than 30 degrees on one end, “but we make that entire area look like a golf course, with the striping and everything,” says Hamby. He mows an even mix of residential and commercial lawns, some flat and some as steep as 45 degrees, and he uses his Ventrac mowers for them all because of the quality of the cut as much as the performance on slopes, he says.
Renae Beegle, marketing coordinator at Ventrac, says, “People come to us when they have a slope they otherwise can’t mow.” She says that for the most extreme situations, available dual wheels on the company’s 4000 series tractors provide stable mowing on slopes up to 30 degrees. “It will go up and down the hill, or it will go sideways across the hill,” she explains. Even given the extreme capabilities of the tractor, it is important for users to first learn the proper operating techniques.
Not all tricky areas involve steep slopes. At the University of Michigan’s North Campus in Ann Arbor, a rather peaceful landform, called “The Wave Field,” features somewhat gentle mounds just 4 feet tall. However, maintaining this unusual site can be an extreme task. “It’s definitely our most challenging area,” says Rob Doletzky, the school’s irrigation and turf manager.
The Wave Field was created by artist Maya Lin, best known for designing the Vietnam Veterans Memorial in Washington, D.C. Like that national treasure, The Wave Field makes a simple but profound statement. “It is a very gentle space that exists on a very human scale. It is a sanctuary, yet it’s playful, and with the changing shadows of the sun, it is completely transformed throughout the day,” said Lin when the landform was created in 1995. “The Wave Field expresses my desire to completely integrate a work with its site, revealing the connectedness of art to landscape, or landscape as art.”
The Wave Field is a landform sculpture “formed to represent the flow of air waves elemental to the study of aeronautics.” Designed by artist Maya Lin, it is located at the College of Engineering at the University of Michigan’s North Campus. Lin is best known for the Vietnam Veterans Memorial in Washington, D.C.
PHOTO COURTESY OF THE UNIVERSITY OF MICHIGAN.
That artistic statement has stood the test of time, but so, too, has the maintenance challenge. “It’s about one-third of an acre, and we mow it with 12-inch-wide ‘cemetery mowers,’” explains Doletzky. These extremely narrow, walk-behind, rotary mowers are essential to follow the contours of the ground without gouging, scalping, flattening or otherwise damaging the uniform shape of the mounds. The grounds staff at the University of Michigan recently began using battery-powered electric mowers. “The time came to replace those little tiny mowers, and we had a difficult time finding something we liked in that width, so we decided to try the electric units,” he explains.
Generally, it takes two people about one hour to do the job, and The Wave Field is mowed twice a week, says Doletzky. “After they finish mowing, they go back through with a string trimmer to do a little more touch-up work on the contouring,” he adds. The same crew is assigned to that area to ensure that experienced hands do the work; again, to limit the chance of damaging the natural sculpture. “It’s definitely a place where we don’t want anything to go wrong,” he says.
One source of damage that’s more difficult to control is the fact that The Wave Field is open to the public and it’s not roped off. “It’s a living sculpture; they encourage people to walk out on it. So, we’ll have busloads of schoolkids that go out there, and the kids love to dig holes. And, because the entire site is built on sand, there aren’t very deep roots, so that can create a rift in the soil,” explains Doletzky. The grounds staff quickly cuts patches of new Kentucky bluegrass sod to repair those areas once they’re spotted. “We’ll have to stake in the patches of sod, literally on a wall,” he adds.
The city of Portland’s International Rose Test Garden was originally designed to evaluate roses, but today it also tests those charged with mowing the intricate lawns between the beds.
PHOTOS COURTESY OF PORTLAND PARKS AND RECREATION.
The 3 or 4 feet of sand beneath the mounds does help alleviate compaction from all the foot traffic, but also poses another challenge. “It takes a lot of water, and it dries out very quickly,” says Doletzky. “We water it about two times a day, three in very hot weather, usually during the day. We saw some disease problems when we watered at night, so we switched to daytime watering and that has helped.” The depressions can trap moisture and block airflow, he explains. There are small pop-up heads in the mounds, as well as irrigation coverage spraying in from around the perimeter. Because of the amount of water required to keep the grass growing, this is the first section of irrigation turned on in the spring and the last to be shut down in the fall, he adds. Fertilizer is applied monthly using hand-held sprayers; push or tow-behind units would be unworkable because of the contours.
Another eye-catching, and difficult to maintain, lawn can be found between West 64th and West 65th Streets in New York City. What’s known as the “Illumination Lawn” was opened last year at Lincoln Center. Although there are no mounds, this patch of grass is far from level. The design, by architectural firm Diller Scofidio + Renfro in association with FX Fowle, is described as “an undulating rectangular surface with two high corners diagonally opposed from one another and two low corners on the opposite diagonal corners.” The lawn is also located on a roof, one story above street level.
The slope ranges from flat to 18 degrees, and that presents a maintenance challenge, says Joe Provenzano, general manager of Kelco Landscaping, which maintains the space. “We have to do everything the old-fashioned way: push mowers, hand clippers, etc., which is really pretty neat,” he says. Crews use 21-inch Lawn-Boy walk-behind mowers and must start early in the morning to avoid creating a disturbance because the lawn sits above a portion of the Lincoln Center. A safety railing surrounds the lawn to protect the public, but the grass runs right to the edge of the roof. “We have to go through a gate and hook on to the fence with OSHA-approved harnesses when we mow that section,” says Provenzano. Clippings are bagged and used to make an organic tea fertilizer, which is applied to the lawn.
The Illumination Lawn is primarily a turf-type tall fescue that incorporates some Kentucky bluegrass. The variety was selected for its ability to stand up to the heavy use the lawn receives for outdoor gatherings and picnics, as well as the fact that it retains some green color during the dormant season. Geoweb mat was anchored to the roof with stainless steel stakes and then filled with 9 inches of a special growing media to help provide the roots with a strong footing for the sloping lawn. A moisture mat was incorporated to help the soil media retain moisture, especially important given the summer heat that can build up on rooftops in New York City. A seven-zone irrigation system was installed to keep the grass watered, and a special drainage system was incorporated to channel any excess water to designated drains.
When mowing the outdoor amphitheater in Portland’s Washington Park, crews use the smallest, lightest push mower they can find to ease the task of lifting the mower up and down steps.
PHOTO COURTESY OF PORTLAND PARKS AND RECREATION.
Across the country, the parks department in Portland, Ore., faces a different kind of mowing challenge at the city’s International Rose Test Garden, as well as a nearby outdoor grass amphitheater in Washington Park. Here again, the use of smaller mowers has helped to overcome the challenge, explains Mike Carr, turf and irrigation supervisor with the Portland Parks and Recreation department. Citywide, the department mows about 1,400 acres per week. “So, we’ve got plenty of mowing going on!” Carr emphasizes. Much of that acreage is handled by 16-foot-wide Toro 5910 mowers, along with 72-inch “trim” mowers.
However, the Rose Garden and amphitheater (both are perennial ryegrass) call for a more delicate approach, and are part of a special “hand-mowing route” that includes some of the trickiest lawns in the parks system. This crew uses Toro 44-inch walk-behind mowers, as well as several 21-inch Toro push mowers. “I would say the Rose Garden is one of the more intense areas we mow; there is a lot of ins and outs and arounds,” explains Carr. The lawn is mowed on a weekly basis and can take the crew as long as five hours to complete.
The use of small, walk-behind mowers allows maintenance crews to navigate the narrow pathways throughout Portland’s International Rose Test Garden without damaging the prized plants.
Carr says that the maneuverability of the walk-behind mower makes it possible to navigate the narrow lawn corridors without damaging the roses or causing compaction, and they’re able to get close enough to the bed that little hand-trimming is required. “They can get right to the edges,” he explains. The mulching mowers do a good job of chopping up cut grass without a need to collect clippings, and there’s no side discharge to shoot clippings on the roses.
In the nearby amphitheater, 44-inch mowers handle the more open outskirts, but the grass stairs and walkways require the small 21-inch units to navigate. “Because of the stairs, we purchase mowers that aren’t self-propelled and are light enough to lift up,” explains Carr. “That’s an approach that we’ve found works best.”
When it comes to tricky sites, thinking outside the box about equipment and mowing strategies can help get the job done no matter how big, small or steep the challenge.
Patrick White is a freelance writer and editor who has covered every aspect of the green industry in the past 15 years. He is based in Middlesex, Vt., and is always on the lookout for unusual stories.