Leaving Little Impact

March 1, 2007

From keeping power line rights of way free from trees that can interrupt power service to keeping recreational lakes and other water bodies liberated from invasive weeds, vegetation management is crucial to many of our day-to-day activities. In fact, the vegetation management business has created a need for a wide variety of tools that help companies, government agencies, and other organizations handle vegetation in a cost-effective and efficient manner. These tools range from herbicides to low-ground-pressure tracked machines that can selectively remove trees and brush. There are even high-tech options available that can sense weeds in pavement and apply a herbicide only when needed.

Keeping the Waters Clear in Florida
Bartow, FL-based Applied Aquatic Management Inc. (AAM) specializes in water management services, selective vegetation control, wetland management, exotic weed control, and industrial and right-of-way vegetation management for clients throughout the state of Florida. The work includes projects for individuals; developers; homeowners’ associations; golf courses; communities; utilities; local, state, and federal government agencies; agriculture; and industry.

“We work for a diverse group of organizations, and some of the projects we manage are very high profile here in Florida,” explains AAM’s general manager, PJ Myers. “Our customers include South Florida Water Management District, Department of Interior, St. Johns River Water Management District, Department of Environmental Protection, and the US Army Corps of Engineers. That means we are working in areas that are extensively used by the public, such as Everglades National Park, Big Cypress National Preserve, and a number of public water bodies.”

Because AAM is working in areas that are used by the public, Myers says the company has to look at safety when selecting a method of vegetation management. “Cost is not the biggest factor here,” he notes. “We have to determine the best way to manage the vegetation, and we have to do it safely. Most of our clients dictate that we don’t have any long-term impact on the native plant communities, so for 95% of our work, we use herbicides that are nontoxic and are tested and approved by the Environmental Protection Agency. For the remainder of our projects, we specify manual labor.”

One of the largest contracts AAM manages is for the US Army Corps of Engineers (USACE) at Lake Okeechobee. The 730-square-mile lake is Florida’s largest lake and the second-largest freshwater lake in the country, second to only Lake Michigan. AAM is now well into its second five-year contract for USACE at Lake Okeechobee.

“Our contract is for the lakewide management of exotic floating species, which are water lettuce and water hyacinth,” explains Myers. “Most of the work is done from airboats and is around the perimeter of the lake and on the vegetation fringes. We also complete biweekly inspections to stay ahead of hot spots or areas that are getting out of control. Ideally, we perform the maintenance on a cycle so that we are always staying ahead of the vegetation.”

To control the water lettuce, AAM uses Reward from Syngenta, and for the water hyacinth, Weedar 64 from Nufarm. “On the lake, there is a great concern with the native plant communities,” adds Myers. “We have very strict guidelines as to where we can apply each herbicide. Anywhere we have exotic species mixed in with native vegetation stands, the USACE says we must use the products that are very selective. For example, Reward is applied at rates that are selective to the exotic species so it doesn’t have a long-term impact on the native vegetation. With species like knotgrass, you might see a visual impact from Reward, but it is short term and it doesn’t kill them.”

The USACE receives funding to look after Lake Okeechobee because it is a federal navigable waterway, and its main responsibility on the lake is to maintain the waterway. “They have to ensure that the interest of all stakeholders in Lake Okeechobee is considered and that includes the growth pattern of the vegetation,” says Myers. “A hyacinth infestation, for example, can double in size in just 10 days, so it is very important to keep it under control so that the lake can maintain a healthy population of native plants and fish.”

Kentucky Wildflowers
Kentucky’s roadsides are looking good these days thanks to a roadside enhancement program that utilizes a mix of state and federal funds. The program was initiated last year by Governor Ernie Fletcher and includes planting both native and non-native wildflowers that produce eye-catching displays on roadside sites. In addition to stimulating tourism by improving the appearance of the state’s roadways, the beautification project also plays a role in managing vegetation along major highways, and in particular at interchanges.

In areas where wildflowers have been established, the amount of mowing for vegetation control has generally been reduced. Most of the wildflowers are annual and need to be mowed down at the end of the season, so the need for mowing has not been completely eliminated. High-visibility areas such as interchanges are the first target of the wildflower program.

In areas that have been selected for wildflower planting, one or two applications of a herbicide such as glyphosate eliminates competition from weeds, turf grass, and other vegetation, and then wildflower seeds are applied with a broadcast seeder. If post-emergence weed control is required, a selective herbicide like Plateau from BASF can be used to remove certain weeds without killing the flowers.

In areas where wildflowers are not planted, Kentucky 31 fescue turf is commonly established.

Indianapolis Wetlands
In Indianapolis, IN, JF New, one of the leading natural resources and ecological consulting firms in the United States, provides full-service vegetation management solutions for the 210-acre Intech Business Park. The company has been involved with the project right from the planning stages and completed wetland delineation on the site and worked with the development team to identify a site layout that would maximize the developable area while minimizing impacts to the identified wetlands. JF New also designed wetland mitigation for the site and prepared the necessary permits and analysis documents.

The company, which is based in Walkerton, IN, employs over 130 people at its offices and facilities around the Midwest. It has been in business for over 15 years and offers a broad range of ecological consulting and restoration services in the areas of wetland consulting, natural resource management, native plant materials, construction, maintenance, and turnkey solutions. JF New also operates one of the largest native plant nurseries in the country and has over 350 available species for use in its own projects and for sale to other companies.

For the Intech Business Park site, the mitigation plans called for incorporating native wetland shelves around the stormwater detention system. The developer committed to this practice because of the resulting aesthetics, despite the fact that it is difficult for native plants to survive because of fluctuating water levels in the stormwater ponds.

JF New also prepared the design/build plans and specifications for the wetlands and recommended and installed all native plants on the site. Much of the water draining into the stormwater ponds comes from the rooftops and the parking lots, so the company incorporated wetland edge plantings and emergent plantings and created a prairie buffer between the lawn areas and the basins to filter out chemicals such as fertilizers that are used on the lawns. Today, JF New manages all of the natural areas of the site to maintain the high aesthetic demand of the business park clientele.

“The Intech Business Park project has been very successful,” says Lisa Herber, a project manager with the Indianapolis branch office of JF New. “Our ongoing role with the business park is to maintain the natural areas around the three detention ponds that are located at the rear of the buildings. There is a walking trail that is used for recreational purposes and seating areas that provide people working at the park with a nice place to sit and have lunch or take a break.”

Herber adds that detention or stormwater ponds can be perceived as a breeding ground for mosquitoes, so plant selection and ongoing maintenance efforts consider the natural predators of the mosquitoes. “If you don’t plant for the mosquito’s predators, it can be problematic,” she says. “Frogs and turtles are attracted to the habitat that we have created, as are dragonflies and songbirds, and this helps reduce the mosquito population.”

During the construction, the site was invaded with weeds, so following the completion of the construction, JF New was hired to handle weekly maintenance. “We do backpack spraying and hand spraying along with some hand pulling of weeds in smaller areas where we don’t need to use herbicides,” explains Herber. “Because it is a wetland area, we want to keep it mostly grasses and flowering plants, so we treat for invasive tree species and shrubs. We really want to emulate what would be there naturally.”

Herber says JF New, as an environmental company, wants to minimize toxins and exposure to toxins, so chemical choice is considered very carefully. “We use low-toxic chemicals that are suitable for wildlife and human use,” she notes. “In particular, we use Rodeo, which is a selective water-based product designed for aquatic use.” Rodeo is an herbicide from Dow AgroSciences.

Herber says the project also creates a great opportunity to educate people about the area. “We are getting lots of positive feedback on the project, and we are seeing this as an educational opportunity for the park users. While we are working, we often have people stop and express their happiness about what we are doing, and we get asked about the different plant species in the area.”

Chemical and Mechanical Mowing
Wanda Davis, manager for the Department of Vegetative Median Maintenance for Hillsborough County, FL, has 6,500 acres of roadside to maintain on a regular basis. According to Davis, the county has tried different methods of vegetation management in the past but recently worked with the Memphis, TN-based Helena Chemical Co. to formulate the right mix of herbicides for effective and safe vegetation control through chemical mowing.

“We were using chemical mowing a few years ago, and then we switched over to mechanical mowing,” explains Davis. “For this new program, which we initiated back in July, we worked closely with Helena to come up with a herbicide-based vegetation management program. Helena is a distributor for a number of companies, and they suggested three primary products for us, including Plateau from BASF and Milestone VM and Garlon 3A, which are both from Dow AgroSciences.”

Davis says Hillsborough County, Tampa, FL, experiences warm temperatures most of the year, and that allows weeds and grasses to get out of control very quickly. “The vegetation was creating a safety hazard for drivers and was also a safety concern for our mowing staff,” she notes. “Initially, we went with just a broad leaf herbicide program, but we needed something more aggressive. So far, we have sprayed 1,600 acres, and that has cleaned up the shoulders and the areas around the guardrails, which has improved visibility considerably.”

Davis says each of the three main herbicides has a different job. “The Milestone is a residual herbicide that will suppress the grass and weeds for 90 days and will then leave a residual that lasts for three to six months. The Plateau is for the suppression of the seed heads on Bermuda and Bahia grasses, and the Garlon is for broadleaf weed control and is especially effective on dog fennel, which is a plant that grows in Florida. We came up with the mix by completing research with Helena and Dow AgroSciences. It is a very minimal rate that includes 2 ounces of Plateau, 7 ounces of Milestone, and 16 ounces of Garlon. We also use 16 ounces per 100 gallons of water of Kinetic, which is a surfactant, in the carrier tank.”

Eventually, Davis wants to have a program where areas will be chemically and then mechanically mowed on an alternating schedule. “We really want to reduce the mechanical mowing because of the cost. Chemical mowing costs about $30 to $35 per acre while mechanical mowing is $60 per acre,” she says. “Also, with mechanical mowing, the vegetation can grow back within a couple of weeks, whereas with the chemical mowing, it can be six months before it needs to be done again. It was the residual factor that really swayed me toward chemical mowing, not only because of the reduced growth but also because of the reduced spraying. With the Milestone, there is not the same perception that we are spraying all the time, which people think of as being hazardous, even though it is not.”

Davis says she tries to educate the public about the sprays and what they are applying and why. “We really don’t get a lot of opposition to spraying and we actually get people calling in all the time and requesting that we come out and spray. I can get a spray truck out in a day, but it might take up to four weeks for us to get a mowing crew out. Also, it takes a lot more tax dollars to move a mowing crew from where they are working to a new site, and with a spray truck I can drive out there myself and take care of the problem.”

The Hillsborough County spray trucks are equipped with Mid-Tech computer systems, which Davis says are the latest technology for spraying. “They can regulate right down to the ounce, which reduces waste, and because they are operated from inside the truck’s cab, the operator is not exposed to the chemicals.”

Keeping Power Lines Clear
As line clearance coordinator for the Upper Peninsula Power Co. (UPPCO), Robert Taggart has the job of keeping power line rights of way free from unwanted vegetation. UPPCO, which is a subsidiary of the Wisconsin Public Service Corp., serves approximately 46,000 residential power customers and 6,000 commercial customers in almost 100 communities in northern Michigan.

For Taggart, focusing on preventative maintenance for vegetation control rather than reactive maintenance allows the company to manage a stable plant community in and around the rights of way and will make high and unexpected vegetation management costs a thing of the past.

“Our goal is to maintain a six-year cycle for vegetation management,” he explains. “We have completed studies that show that vegetation in our area, once pruned, will grow for six years before it starts to interfere with our wires and cause power outages for our customers.”

Taggart is not dealing with small and annoying weeds. He has to contend with a “vast forest” of fully mature trees that include various species of red and sugar maple, aspen, birch, black cherry, red pine, jack pine, black spruce, tamarack, and various types of cedar. “One of the areas we just dealt with had not been cleared in over 40 years, so we had to completely clear the right of way of everything,” he adds.

Where possible, UPPCO crews go in with a bucket truck. One crew member in the bucket will use a pole saw to remove the high branches while crew members on the ground feed the branches into a chipper and handle floor vegetation. The bucket truck works well for roadside areas, but for much of the hilly and rocky terrain in upper Michigan, Taggart says they will use a Hydro-Ax machine, which is a rubber-tired tractor with a brush attachment, to treat the floor. They also use a skidder with a bucket attachment to handle the high pruning in remote areas.

Following the removal of the larger brush, UPPCO will often spray a herbicide mix to control the vegetation between cycles. “For us, this program is about safety, saving money, and providing our customers with reliable power delivery,” notes Taggart. “In terms of cost, studies conclude that for every year we let the vegetation grow past the six-year mark, maintenance costs will increase by 7%. Not only that, if we stay on that cycle, our reliability increases because we don’t have large trees falling on our lines, and that also improves safety for our employees and the public.”

Walter Oliver of Oliver’s Bushhogging in Beaufort, SC, has built his business around clearing vegetation. The company, which was established in 2001, completes projects such as underbrush removal for developers, clearing survey lines for survey companies, cleaning up after loggers, removing brush from power line easements, and even cutting trails for horse riders and hikers.

“We do a real mix of jobs,” says Oliver. “A big part of our business is working for commercial and residential developers, but we have worked on all kinds of projects where vegetation has to be removed.”

For development projects, Oliver says his are generally the first crews on a site as underbrush needs to be removed so that the survey crews can get clear site lines and so that everyone can see what they have to work with. He says underbrush, or under story, is anything that is 8 or fewer inches in diameter at chest height.

Oliver’s tools of the trade include six low-ground-pressure track machines from Gyro-Trac USA Inc., including the first machine the Summerville, SC, manufacturer produced. “We have larger Gyro-Trac machines with dedicated brush cutters, and we have some smaller machines that can use various cutting or mulching attachments,” explains Oliver.

With his fleet of Gyro-Trac equipment Oliver’s crews can be selective when removing vegetation, which means they can leave some areas or tress for wildlife, they can create riparian management zones around wetlands and creeks, and they can work in wetland areas because of the low ground pressure offered by the machines. “In some wetland areas, only certain types of machines are allowed to be used, including ours,” says Oliver. “The ground pressure is very low so our equipment doesn’t disturb the natural landscape. When a 160-pound human walks in these areas, the ground pressure is 6.2 pounds per square foot. The Gyro-Trac machine is half of that at 3.1 pounds per square foot.”

Targeting Weeds
Vegetation management isn’t always related to large trees and brush. At the City of Lakeport, which is in California’s wine country and situated on Clear Lake, Public Works Superintendent Doug Grider is dealing with smaller weeds that push their way through cracks in the pavement and other areas such as where the roadway butts up to the gutters.

For Grider, high tech has proven to be the answer as the city of 5,000 people has equipped the local street sweeping machines with WeedSeeker automatic spot spray systems from NTech Industries Inc. in Ukiah, CA. The patented WeedSeeker technology uses advanced optics and computer circuitry to sense if a weed is present. The sensor has a 12-inch-wide field of view, and when it detects a weed, it signals a spray nozzle, which then applies a predetermined amount of herbicide such as Roundup.

“The sensor detects the plant, and once the weed is dead, the equipment will no longer detect it,” explains Grider. “Because the spray nozzle only activates when the equipment detects live weeds, we are not spraying pavement, which makes this program very cost-effective.”

The Lakeport sweepers are each equipped with two WeedSeeker systems on the rear of the sweeper. The street sweeper simply follows the usual route, and the WeedSeeker comes on when needed. “Like most rural areas, we don’t have the funds to do everything we would like to do when it comes to controlling weeds, so this is a very good way for us to control the weeds along the gutters and roadsides,” says Grider. “It is really simple to use, and the operator has a route map that identifies any properties where the owners don’t want us to spray. They control it from the cab of the sweeper and just turn off the sensors in these areas.”

For a small city like Lakeport, Grider says the technology makes economic sense. “By having the WeedSeekers on the sweepers, we are really doing two jobs at once, and that helps us out tremendously in terms of budgets,” he adds. “Before, we were using a truck with a hose running out of it, which meant the operator had to stop and get out of the truck to apply the herbicide. It was very time consuming. Now, everything is controlled from inside the truck. We are estimating the payback on the WeedSeeker equipment will be 18 to 24 months. After that, it is just cost savings.”
About the Author

Bill Tice

Author Bill Tice is based in Blaine, WA.