Weed profile: Virginia creeper

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Virginia creeper (Parthenocissus quinquefolia) is a native North American, perennial woody vine, which can easily climb 30 feet or higher. Its tendrils end in oval shaped disks that adhere to surfaces and can damage stucco, the mortar between bricks, and painted surfaces. This highly adaptable plant grows in full sun to full shade. Grown as a groundcover, it can provide erosion control on slopes. Virginia creeper is very drought tolerant and a vigorous grower.

With adequate sunlight, Virginia creeper leaves turn a brilliant red in the fall, and the vines produce dark blue berries that are valued by birds and other wildlife.

Although Virginia creeper is often confused with poison ivy, Virginia creeper has five leaflets, while poison ivy has three. Virginia creeper leaves have saw-toothed margins, whereas poison ivy leaf margins are highly variable. Although Virginia creeper leaves does not contain urushiol, the irritating oil found on all parts of poison ivy, the sap can irritate highly sensitive people. The berries are poisonous, as they contain a high concentration of oxalic acid, which is moderately toxic to humans and dogs.

A troubling connection

Danny Lauderdale, area specialized agent for ornamental nursery and greenhouse at North Carolina State University Extension, says Virginia creeper is commonly seen around the perimeters of nurseries and occasionally in the crops themselves. It also attracts the red headed flea beetle, a voracious pest that has been vexing nurseries lately. The beetle likes to eat the tender growth of this weed.

Lauderdale suggests that growers make sure they manage their weeds and look for RHFB populations around the perimeter. Once the beetles are feeding on the weed, they will move on to other plants nearby, including your valuable crops.

“When I go visit nurseries, I don’t even have to ask if they have a red-headed flea beetle problem a lot of the time,” Lauderdale says. “If I pull up to a nursery and I see a lot of weeds in the roadway, in the plants, I know it probably has red headed flea beetle. If I pull up and it’s a real clean nursery, they probably don’t have RHFB.”

Lauderdale says it’s about management and a nursery that allows weeds like Virginia creeper to penetrate its perimeter and provide a food source for this pest are more likely to have problems.

“If they’re on top of their weed control, they’re probably scouting, they’re catching things early,” he says.

Photo © Roxane Bay; Adobe Stock

Control

As a perennial weed, Virginia creeper will be tough to control as it can easily regrow after foliar injury from its extensive underground root system. When established, Virginia creeper will most often not be controlled with a single herbicide application, and multiple applications will be necessary to achieve acceptable control. Only nonselective postemergence herbicide (glyphosate) must be used to suppress or control this weed. To increase the efficiency of postemergence applications during the growing season, remove the vine from their support during winter pruning and lay it on the ground or plan a “cut stump” treatment during the growing season. Do not “prune out” the vine during the dormant season.

Spot treatment: Glyphosate may be applied in mid- to late summer after vine flowers in early July until the first signs of fall color appear in the foliage. Good growth and maximum leaf area is needed at the time of herbicide application during the summer. Wet a minimum of 50% of the weed foliage with a 1% glyphosate solution (1.25 oz of 4.5lb acid material per gallon of water) for effective control. For best control, don’t apply on stressed/wilted weeds.

Cut stump treatment: Best results are often obtained in late summer and early fall, but before fall color is observed in the foliage. Apply a 1% glyphosate solution to the cambial areas (inner bark area) of the stump of woody plants immediately after cutting. Cut and treat stumps only when the Virginia creeper is actively growing and not under stress.

Source: Clemson University, Rutgers University, NCSU