Roadside Vegetation Management Innovators – NCDOT, Raleigh, NC.

North Carolina has the USA’s largest State maintained highway system consisting of 78,000 miles (125,500km) of highways. This equates to over 331,000 acres (54,000ha) of rights of way maintained in three general forms: turf, natural areas, and landscape plantings.

The Project Representatives spent an extremely productive few days with the staff from North Carolina Department of Transport (NCDOT) Roadside Environmental Unit inspecting a range of field sites and some of their latest spray application equipment. Photos from the visit can be viewed on the IVMP website in the image gallery.

Everything is done a massive scale due to the size of the area that is under management, however there is a lot we can learn from their methodologies and equipment, scaled down to meet our needs in Australia.

A standout for this part of the trip would have to be the commitment NCDOT has put into better managing their roadside vegetation. NCDOT’s Roadside Environmental Unit, works in cooperation with 14 divisions statewide covering three climate zones that include multiple cool and warm season grass species, as well as varying soil conditions.

The professionalism, dedication and commitment of the team were apparent as were the results of their hard work. With strong partnerships with researchers from North Carolina State University (NCSU) and significant levels of funding allocated for research and development, NCDOT has implemented innovative roadside vegetation strategies that have not only save millions of dollars, they have also significantly improved the safety levels for road users and those who maintain these road networks.

NCDOT have taken a long term view with their roadside vegetation management strategies. They are prepared to invest significant funding in the short term knowing that in the longer term the benefits will out way the initial investment.

A number of the innovative practices and vegetation management methodologies developed by NCDOT in conjunction with NCSU would be worthy of implementation in Australia. The IVMP project will now explore a number of these innovations, with the support of both NCSU researchers and the NCDOT’ Roadside Environmental Unit.

Australia can learn a lot from the efforts of NCDOT in the management of roadside vegetation. As the costs of maintaining road networks increases, funding for roadside vegetation management is under pressure. Innovative ways to reduce the triple bottom line cost of managing roadside vegetation is more essential than ever, and funding dedicated towards this cause will pay handsomely in the future.

We would like to know what innovative practises you are using to manage roadside vegetation? Was the last innovation in vegetation management for Australian roadside vegetation the weed wiper? What other innovations are out there?

With regard to funding research and development projects for mown vegetation is anyone investing in innovation now with an expectation of reaping the rewards through future savings?

We welcome your comments, questions and feedback.

Appropriate funding = high quality sports surfaces

Situated in the heart of the ‘Triangle’ area of North Carolina between Raleigh and the Research Triangle Park, Cary is a relatively small town by US standards of 120,000 residents.

North Carolina has a relatively high rainfall average of 45 inches (1140mm) and high summer humidity similar to South East Queensland. Because of this they have many of the same problem species and challenges, for example the fast growing Bahia grass Paspalum notatum.

Project Representatives met with the Town of Cary’s Parks & Recreation staff and inspected some well maintained soccer and baseball facilities, including a new one where the US Olympic baseball team is currently training.

The USA Baseball National Training Complex is located in Western Cary and was selected to be the new home of USA Baseball in 2002.

The National Training Complex has four baseball fields, which consist of one Stadium Field and three Training Fields that are all fields are maintained at Major League Baseball standards.

WakeMed Soccer Park, a 150-acre multi-use complex operated by the Town of Cary. The park hosts professional matches, college and high school tournaments and other events. Fields are available for field sports such as soccer, youth football, lacrosse and ultimate Frisbee. The park also includes a world-class cross country course that encircles the park.

The level of professionalism, pride of workmanship, and access to the best technologies and funding have ensured that Cary’s Parks & Recreation staff have sporting fields of the highest standard.

It is clear that with the appropriate expertise and the right level of funding a high standard of sporting surface is achievable. However, our experiences have shown that funding to manage sporting surfaces has never been sufficient to ensure a high quality sporting surface in most situations.

We would be very interested to hear back from sports turf managers about whether they have the budgets they need to deliver high quality sporting surfaces. What sort of funding is required to provide a high quality sporting surface? Have safety concerns raised the profile of sports turf management and ensured additional funding is being available. We welcome your comments, questions and feedback.

Photos taken during our visit to the USA Baseball National Training Complex and WakeMed Soccer Park are available on the IVMP website image gallery

New uses for generic technologies and new technologies for niche markets

The Project Representatives met with the supervisor of San Diego County’s integrated pest control program. California has an additional ‘County’ layer of government which fits between the city and state government municipalities.

They are the regional government that provides health and justice services to all 3 million residents of San Diego County and municipal services to the county's unincorporated areas. Their pest department undertakes an extensive roadside spraying program of county roads with a fleet of aging tankers using Raven spray equipment and Radiarc spray heads.

We learnt a great deal about products and application equipment but one of the standouts is the use in California of an aquatic Imazapyr product called Habitat.

Habitat herbicide has received full label approval from EPA, labelled for the control of undesirable emergent, shoreline and woody wetland aquatic vegetation in and around standing and flowing water.

Habitat herbicide controls vegetation by affecting enzymes found only in plants, not in humans, animals, birds, fish or insects. It is readily absorbed through leaves, stems and roots and is translocated rapidly throughout plants, with accumulation in the meristematic regions. Treated plants stop growing soon after spray application. Necrosis becomes evident about two weeks after treatment. Time to death of treated weeds depends on size, species treated and weather conditions at application.

Habitat is a systemic herbicide that delivers down-to-the-roots aquatic and riparian weed control, enabling users to cost-effectively reclaim and maintain waterways and wetlands that have lost value to emergent invasive species.

As many roadside environments adjoin wetlands, environmentally sensitive areas or are classified as drainage systems this product would be of tremendous benefit to industry and the Australian public if made available in this country. With this in mind the active ingredient Imazapyr is off patent and the IVMP Technical Team will consider this active for inclusion in future trial work.

We have previously raised the issue with regard to the lack of funding to support expanded uses of generic technologies or new technologies for niche markets that are not big enough to be of interest to the chemical companies.

In such situations there are opportunities to seek off label special use permits. This offers vegetation managers a broader range of choices when trying to manage weed populations but the process can be time consuming and difficult to get approved.

So our question would be who should be doing the work required to ensure vegetation managers get access to the right tools to manage an every increasing range of weeds? We welcome your comments, questions and feedback.

The image gallery on the project website has photos from the visit to San Diego County.

NCDOT's Integrated Roadside Vegetation Management

NCDOT has developed a system for coordinating the management of roadside vegetation to maximize the effectiveness of both operations while increasing cycle times between mowing operations.

The Integrated Roadside Vegetation Management (IRVM) is a decision-making and quality management process for maintaining roadside vegetation that integrates cultural, biological, mechanical, and chemical pest control methods to economically manage roadsides for safety plus environmental and visual quality.

In developing the IRVM system the following factors are also considered:

• needs of local communities and highway users
• knowledge of plant ecology processes
• design, construction, and maintenance considerations
• monitoring and evaluation procedures
• government statutes and regulations
• technology

Integrated Roadside Vegetation Management (IRVM)is a spin-off of the Integrated Pest Management (IPM) concept used in agriculture, horticulture, and forestry. Integrated Pest Management (IPM) is a term used to describe a system of managing pests whereby all possible methods of reducing pests are combined (integrated) to maintain (manage) pest levels below economically damaging levels. IPM employs proven practical and least costly methods in a plan designed to exclude pests from the management unit.


IVRM is used to manage vegetation by simply applying logical information, communication, technology, planning and research.

An effective IRVM program improves safety for the public and employees, satisfies long-range economic goals, maintains or improves quality, provides aesthetically pleasing facilities, and improves public relations. The highest priority for NCDOT employees is supplying safe transportation corridors with hazard- free safety clear zones, low growing vegetation in the operational zone and open sight distances.

Those involved with the Integrated Vegetation Management Project (IVMP) in Australia are looking to develop a model spcifically suited to Australia's conditions. We welcome your thoughts on the subject and invite you to visit the IVMP website for further information.

Managing the costs of maintaining sports turf

Project Representatives met with the superintendent of the City of Coronado Golf Course, right under the famous Coronado Bridge and directly opposite the Navy Seal training facility.

Coronado’s fairways are a mix of kikuyu and green couch and once again we were able to get a first hand view of how they manage their facility with limited rainfall.

The Superintendent uses plant growth regulators (PGRs) on the course to keep the Kikuyu under control and reduce maintenance costs. He had a number of new herbicide technologies available to manage weeds and used pre-emergents to manage the most difficult areas of weeds.

For the Superintendent, the biggest challenge is the mounting cost of the potable water used to irrigate the course. Coronado doesn’t have access to recycled water so they irrigate with potable drinking water... to the tune of $400,000 US last year.

The use of water for amenity horticulture purposes is an issue we have been grappling with for many years. What strategies have you implemented to reduce water usage in these areas? Are you moving towards recycled water for these areas and do you have strategies in place to counter the effects that water will have on the soil profile and plants you are irrigating?

Are you using PGR’s as part of a broader strategy to reduce water usage? What are you using …and how effect has it been? I welcome your comments, questions and feedback. Images from the visit to Coronado Golf Course can be viewed in the image gallery on our project website.

Introduced roadside vegetation a problem in California

The City of Poway has a population of approximately 51,000 residents and is located in northeast San Diego County. Poway is known as “The City in the Country” and prides itself on the fact that over half of the City’s area is preserved as dedicated open space.

Poway has a population of approximately 50,000 and is located in northeast San Diego County. Poway is known as “The City in the Country” and prides itself on the fact that over half of the City’s 39.4 square-mile (100km2) area is preserved as dedicated open space.

San Diego is very dry, only receiving 4.5 inches (120mm) of rainfall last year, so we learnt a lot about how they manage their public open space vegetation with limited rainfall. A large percentage of their state controlled roadsides are planted with a monoculture of ‘Ice Plant’ Carpobrotus edulis.

In the early 1900s C. edulis was brought to California from South Africa to stabilise soil along railroad tracks and was later put to use on road networks for similar purposes. Thousands of acres were planted in California until the 1970s. It easily spreads by seed (hundreds per fruit) and from segmentation (any shoot segment can produce roots). Its succulent foliage, bright magenta or yellow flowers, and resistance to some harsh coastal climatic conditions (salt) have also made it a favoured garden plant. The Ice Plant was for several decades widely promoted as an ornamental plant, and it is still available at some nurseries. Ice Plant foliage can turn a vibrant red to yellow in colour.

The Ice Plant is still abundant along highways, beaches, on military bases, and in other public and private landscapes. It spreads beyond landscape plantings and has invaded foredune, dune scrub, coastal bluff scrub, coastal prairie, and most recently maritime chaparral communities. In California, the Ice Plant is found in coastal habitats from north of Eureka, California, south at least as far as Rosarito in Baja California.

The Ice Plant poses a serious ecological problem, forming vast mono specific zones, lowering biodiversity, and competing directly with several threatened or endangered plant species for nutrients, water, light, and space. This species introduction, brought in to assist in erosion control and to reduce maintenance sends a warning to roadside vegetation managers that care must be taken when species to ensure they are beneficial to the environment they are used in and not an ecological disaster.

We would like to know what weed species you are battling with in your built environment. Do you to have introduced species that you are finding difficult to manage? What can we do in the future to ensure we do not make the same mistakes in the future?

We welcome your comments, questions and feedback. Visit our website to view photos of the harsh roadside environment and the use of Ice Plant in roadside situations.