Rights-of-Way

Highway, railway, and utility rights-of-way serve as major corridors in the spread of invasive plants from place to place in the United States.

Hay, spread as mulch in roadside planting projects, can enable invasive plants to spread into previously uninfested areas. Use of weed-free hay helps to prevent the spread of serious weeds. (C. Bryson, USDA Agricultural Research Service Stoneville, Mississippi.)

FACT: Invasive plants increase road maintenance costs. Invasive plants such as purple nutsedge grow up through cracks in asphalt and concrete, causing increased maintenance costs.

FACT: Invasive plants can obscure vision at intersections. One of the most serious problems associated with invasive plants is obscuring vision along transportation routes. Tall plants encroach on highway intersections, block the view of motorists, and can cause severe accidents.

Invasive plants such as johnsongrass complicate roadside vegetation management programs, create safety hazards by obscuring visibility and increasing the intensity of roadside fires, and provide seed sources for infestation of adjacent fields.( B. Harper-Lore, Federal Highway Administration, Minneapolis, Minnesota.)

FACT: Invasive plants are spread by mowing equipment. Mowing prevents reproduction of some weeds, but can accidentally spread the seeds of weeds like knapweed in the Midwest and the dustlike seeds of parasitic weeds such as small broomrape in south Georgia.

FACT: State departments of transportation each spend at least $1 million per year in vegetation management. Introduced weeds complicate and raise the cost of these programs. The use of weed-free hay as mulch in roadside planting projects minimizes introduction and spread of unwanted plants (Bonnie Harper-Lore, Federal Highway Administration, Washington, D.C., personal communication, 1997).

Itchgrass was introduced into Florida from the Philippines in the 1920s as a potential pasture grass. It is shown here beginning to infest a roadside wildflower plot in North Carolina. The contaminated seeds originated in Texas. (G. Cross, North Carolina Department of Agriculture, Raleigh, North Carolina)

FACT: Invasive plants are spread along highways and railways.Weed seeds that become attached to vehicles, earth-moving equipment, and railway cars can be spread for hundreds of miles. Itchgrass, a serious grass weed of sugarcane and other crops in the Gulf Coast states, has been spread by trains. Once established along a railway, weeds such as itchgrass then spread into adjacent fields (David Hall, Forensic Botanist, Gainesville, Florida, personal communication, 1997.)

FACT: Invasive plants can obstruct access to power and gas lines. Utility rights-of-way are heavily disturbed but minimally maintained. Therefore, they serve as ideal sites for invasive plants to become established and spread. Heavy weed populations can also obstruct access to power and gas lines.

Invasive plants in roadside wildflower plots. In the past, some state beautification projects deliberately seeded plants such as purple loosestrife along selected roadsides. After becoming established, such plants may spread into adjacent crops and/or natural areas. However, in recent years, state highway agencies have become knowledgeable about the problem of invasive plants and how to deal with them. In 1994, the North Carolina Department of Transportation cooperated with the North Carolina Department of Agriculture to eradicate several small populations of itchgrass from roadside wildflower plots. In this case, itchgrass was found to be a contaminant of wildflower seeds that had been planted by the North Carolina Department of Transportation. The wildflower seeds originated in Texas (Gene Cross, North Carolina Department of Agriculture, Raleigh, North Carolina, personal communication, 1997).

Yards & Gardens

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Rangelands & Pastures