In the weeds

May 17, 2002

In roadside maintenance, unlike in golf, long grass is OK. But like in golf, you want to get rid of the unsightly weeds. Last September, the National Roadside Vegetation Management Association (NRVMA) met in Waco, Texas, to discuss the inside story of how to keep the nation’s roadsides tidy. The leader board included four organizations that were presented with the association’s annual awards for excellence in managing roadside vegetation.

In roadside maintenance, unlike in golf, long grass is OK. But like in golf, you want to get rid of the unsightly weeds. Last September, the National Roadside Vegetation Management Association (NRVMA) met in Waco, Texas, to discuss the inside story of how to keep the nation’s roadsides tidy. The leader board included four organizations that were presented with the association’s annual awards for excellence in managing roadside vegetation.

The winners for 2001 were organizations that exemplified NRVMA’s commitment to the safety and beautification of the nation’s roadsides through responsible caretaking. The tools at the vegetation manager’s disposal include various herbicides, mowers, native seeds, landscaping and a few others.

Roads & Bridges interviewed the winners, including the city of Duluth, Minn., which claimed top honors in the city category. Other winners were the Florida Department of Transportation (state DOT), Great Bend, Kan., (county), and Becker Underwood Inc., Ames, Iowa, (support).

Know your climate

Tom Kasper was “knee-deep” in planting flowers and other plants in mid-April when he made time to talk with Roads & Bridges about the program in Duluth. Kasper is the supervisor of park maintenance for the city and oversees, among other things, six parks along I-35, which skirts Lake Superior. The parks cover a total area of about 40 acres. Some of them are located on top of tunnels over the freeway.

“We’re adding a new garden within the rose garden that will have more hardy shrub roses,” said Kasper, who has a budget of about $100,000. The rose garden, which has 3,000-4,000 rose bushes on about 5 acres, is nationally recognized.

Another nationally recognized garden along I-35 is home to the Duluth International Sculpture Garden.

Kasper and his staff do routine pruning of the trees and shrubs in the parks. They also run a weed abatement program that depends on the help of the community.

“We’ve adopted a policy in the city of Duluth to minimize the use of pesticides in our plans,” he explained. “Adhering to that does cost us more in labor. However, I get a lot of youth groups and volunteer groups that help us along this corridor.”

Much of the weed pulling and mulch-ing is done by these helpers who put in about 2,000-3,000 volunteer hours each summer. A local rose society, for instance, assists in maintaining the rose garden.

The rose garden gets most of the pesticides Kasper uses in these parks.

I-35 was completed through Duluth in 1994, and that is when these parks began being established. They have thousands of spring- and summer-blooming perennial plants, trees and shrubs. Kasper and his staff also plant some 30,000 annuals throughout the year.

“All of our turf areas are designed for minimal need for hand work,” Kasper commented. “Ninety-five percent of it can be mowed from the seat of a lawn tractor. We mow most of these areas once a week during a normal summer. Many of these areas are also under irrigation. The grass is well maintained and fertilized.”

Kasper would like to dispel the myth that Duluth, in northern Minnesota, is frigid most of the year.

“That’s a common misconception with Duluth, but because we’re on the shore of Lake Superior we have a very moderate fall,” he said. “We have annuals that are in bloom late into October.”

Lake Superior moderates the temperature in summer as well. When other parts of the state have temperatures in the 90s, the temperature within a few miles of the lake is in the 70s.

Perhaps the moderate climate accounts for the fact that Duluth is a popular tourist destination. About 3.5 million visitors per year recreate by the lake. In return, Duluth has made a substantial investment in its road- and lakeside parks.

Beautification by statute

The state of Florida has adopted the philosophy of planning roadside beautification at the same time it plans highway construction, and it wants to make those beautiful roadsides as easy to maintain as possible.

“What happens when you wait until the maintenance phase is that you want to do landscaping, but the opportunities have been missed,” Jeff Caster, Florida’s transportation landscape architect, told Roads & Bridges. “You may want to plant trees down the median, but the medians aren’t wide enough to plant trees.

“We’re going to consider the desire for highway beautification during design and construction,” he continued, “so that we can maximize the opportunities for highway beautification.”

Beautiful highways include the usual things—wildflowers, grass, trees—but Caster emphasizes the need to find the right plant for the right location. The Florida DOT breaks the state into eight regions, each of which has its own landscape architect with expertise in the region’s vegetation.

Part of finding the right plant is being able to get seeds of native plants, and finding those seeds is a problem: “The problem is universal almost. If you’re in any place in the country and you’re working on a restoration project or even a beautification project and you want to plant native species and you want to use seeds that are from truly native plants that are genetically from the area where you’re planting, typically those seeds are not available.”

Gary Henry, Caster’s predecessor who retired recently after 30 years with the Florida DOT, was an activist for the availability of native seeds. Orlando, Fla., hosted the conference “Seeds for the Future” on April 18-20, 2001, to discuss the subject of native seeds.

A few years ago, the Florida state government decided it wanted even more highway landscaping, so it passed a law allocating 1.5% of the state’s highway construction budget for landscaping.

“So, as our highway construction budget goes, so does our highway beautification program,” remarked Caster. “Depending on whose numbers you look at, suddenly we have about a $25 million highway beautification program that is required by Florida statute.”

Along with doing landscaping work of its own, Florida’s DOT gives grants to local governments through the Florida Highway Beautification Council made up of private citizens.

Caster and his staff try to design roadsides that will need minimal maintenance: “Lots of trees. We find that trees, once they’re established, if the right tree is planted in the right place, they require the least amount of maintenance.” He plants the trees in large stands to avoid having to mow around each one individually.

Other things they look for in landscape designs include little or no irrigation, dual function (e.g., noise abatement, visual screening), enthusiastic community support, safe maintenance procedures and of course beauty.

Landscape beauty is more than colorful flowers, according to Caster. “There’s infinite varieties of green,” he explained. “If you just mix up the tones of green and the different textures that are available to you, you could have a really beautiful, interesting landscape.”

Weed wars

Florida has a problem with invasive species of vegetation and is exploring the possibility of using prescribed fire in limited areas in addition to chemical and mechanical controls. The Barton County Noxious Weed Department is focused on less drastic measures.

Barton County is a rural area of Kansas. Dale Phillips is in charge of the Road and Bridge Department as well as the Noxious Weed Department. The county is 900 sq miles in area and has 389 miles of asphalt county roads. Phillips, his assistant director, Kate Thompson, three herbicide applicators and two part-time secretaries are responsible for keeping those roads clear of weeds.

Phillips and his staff in the Noxious Weed Department face primarily four species of weeds in the county: bind weed, burr ragweed, musk thistle and johnson grass.

Their strategy is to use a combination of pre-emergent herbicide, spot herbicide to kill patches of weeds that crop up, planting native grasses and mowing.

Phillips finds that if he can establish native grasses, he can mow less often.

“We used to mow five times a year,” he said. “Now we’re mowing three times a year and maintaining native grasses versus having a considerable amount of nondesirable vegetation out there.”

Mowing three times a year instead of five saves the county about $50,000 out of a $110,000 budget for mowing and a $55,000 budget for spraying. The goal is to keep saving money on mowing and get the roadsides onto a reduced herbicide maintenance program as well.

“You should get to the point where the native grasses would go ahead and flourish without these treatments,” Phillips said. “And that’s the goal, that we can skip a couple years and then save money and then just go to a maintenance program.”

They time their mowing to accommodate the local wildlife. On the first pass of the mowing season, they might mow only 15 ft out from the road on a 30-ft right-of-way. Mowing only part of the right-of-way discourages deer from hiding in high grass near the road, yet gives wildlife like pheasants, for instance, a chance to hatch their eggs. The maintenance crew then mows the rest of the right-of-way a little later in the season.

“We’ve worked on this program essentially since 1987,” concluded Phillips. “We skipped a year or two in between there, but what it amounts to is that we have brought back our native grasses on our roadsides, which are more desirable for mowing and maintaining that. And it helps everyone in our county to have safer roadsides.”

Spray your troubles away

All of the winners of this year’s NRVMA awards might make use of the products of Becker Underwood Inc., Ames, Iowa. The company makes colorants for vegetation management.

“The application for a colorant in vegetation management is that it’s used as an indicator so the applicator can see where they have sprayed,” Cozette Hadley, vice president of distribution sales, told Roads & Bridges.

Hadley said the colorant has no effect on the plants it is sprayed on or the pesticide it is mixed with. It also has no effect on the performance of the spraying equipment. In fact, it might be beneficial by showing visibly where a hose is leaking or a nozzle is not spraying properly.

The colorant, called Hi-Light, breaks down and disappears in about 48 hours. It is broken down by the ultraviolet rays in sunlight. It also is water soluble, so a rain shower will dilute it and wash it away.

Hi-Light comes in red and blue colors and in the form of a liquid, a soluble packet that can be dropped right into the pesticide tank or a tablet.

Becker Underwood also makes colorants for color-enhanced mulch and seed colorants and coatings. Fade-resistant color-enhanced mulch is used in landscaping projects for aesthetic value. It also has the benefit that it is made of recycled wood materials, Hadley said.

“It has the advantage of creating a market for something that otherwise has a very limited value.”

One of Becker Underwood’s latest products is a nematode called Steinernema scapterisci. It is an insect-parasitic round worm that will invade the body of a mole cricket and kill it. Mole crickets are a special and damaging breed that was introduced to the U.S. accidentally from South America at the turn of the 20th century. They now inhabit the southeastern U.S. and do a lot of damage to turf grass areas.

“Mole crickets burrow in the soil,” said Hadley, “and in doing so they really disrupt the root system of turf grass.”

The S. scapterisci species of nematode is a natural enemy of mole crickets and helps to control the mole cricket population in South America.

In tests, the nematode was almost 100% effective against mole crickets and posed little or no threat to other U.S. insects.

Whether it is fighting burrowing crickets with microscopic worms or simply chopping the weeds down with a tractor mower, roadside maintenance departments and highway beautification departments across the country are on the front lines of the battle to keep the good vegetation in and the unwanted vegetation out.

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