By Elaine Mills, Extension Master Gardener
Another “top ten” invasive plant in Arlington County is multiflora rose (Rosa multiflora), a perennial shrub introduced to the United States from Asia in the 1860s as rootstock for ornamental roses. It was subsequently recommended by state conservation departments to provide erosion control, provide cover for wildlife, serve as an economical “living fence” to confine livestock, and provide a buffer for highway medians. It has since escaped from these plantings and now poses a serious problem throughout the eastern half of the United States.
The long, arching stems of multiflora rose allow it to climb over other plants, and it can grow as much as 1 to 2 feet per week to form impenetrable thorny thickets in abandoned pastures, roadsides, forest edges, and open woods. The plant has compound leaves and abundant clusters of showy white flowers from April to June. Bright red rose hips, each containing 6 to 12 seeds, develop in the summer and remain through the winter. This invasive alien can be distinguished from desirable native rose species by its flowers, which are white rather than pink, and by the fringed stipules at the base of its leaf petioles.
Multiflora rose aggressively colonizes natural areas via seeds and vegetative reproduction. One plant can produce up to 500,000 seeds, which are distributed over long distances when birds such as robins, cedar waxwings, and cardinals consume the fruit. These seeds remain viable in soil for 10 to 20 years. The shrub can also spread through layering which occurs when cane tips touch the ground and grow roots to form new plants. In this manner, a single rose seedling can produce a patch more than 33 feet in diameter. Other advantages over potential competitors are the plant’s early leafing in the spring and its vigorous root system that can persist for many years.
This invasive plant can be difficult to control, but several mechanical and chemical methods are recommended. Biological control programs using disease and seed predators are currently being investigated. For more details, see the related fact sheet, Least Wanted: Multiflora Rosa by the Plant Conservation Alliance’s Alien Plant Working Group.
- Invasive in the Spotlight: Multiflora Rose. University of New Hampshire Extension
- Least Wanted: Multiflora Rosa. Plant Conservation Alliance’s Alien Plant Working Group. National Park Service
- Multiflora Rose. Invasive, Exotic Plants of the Southeast. NC State University
- Multiflora Rose (Rosa multiflora). Connecticut Invasive Plant Working Group. University of Connecticut.
- Multiflora Rose (Rosa multiflora). Ohio Perennial and Biennial Weed Guide. Ohio State University