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Removing multiflora rose: How to handle the invasive species we once welcomed


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Early spring is a great time to begin scouting around the yard or garden area and removing early-season invasive species and noxious weeds.

A noxious weed is considered harmful to the environment, to wildlife, and to agricultural and horticultural areas. For this reason, sales of noxious weeds have been restricted in many states. One such weed that has a widespread infestation is the multiflora rose.

The multiflora rose has its origins in East Asia. Since its introduction in the 1860s, this noxious weed has spread across much of the Eastern United States and Canadian provinces and the Midwest, with some scattered findings in Oregon.

Multiflora rose was initially seen as having benefits as a living fence, as food and shelter for wildlife, and as a way to control soil erosion. In the 1960s and '70s, multiflora rose was planted along highway median strips for crash barriers and as a means of reducing headlight glare for night driving.

Multiflora rose poses threat to wildlife diversity

Multiflora rose has attractive fragrant flowers that bloom in the spring, leaving some gardeners unwilling to remove this plant due to its perceived aesthetic value. However, we now know that the dense growth created by this prolific plant degrades natural environments, reduces native plants, and is a serious threat to wildlife diversity.

Multiflora rose invades open woodlands, forest edges, old fields, roadsides, savannas and prairies. It tolerates various soil and environmental conditions, grows in full or partial sun, and does best on well-drained soils.

Multiflora rose can produce 500,000 seeds annually

Multiflora rose can grow to reach 10-15 feet tall and 9-13 feet wide, but typically is more of a sprawling, spreading plant than an erect one. When established, it will form impenetrable thorny thickets.

Each plant can produce up to 500,000 seeds per year with the seeds remaining viable in the soil for up to 10 to 20 years. The seeds of multiflora rose fall off relatively close to the parent plant but are widely dispersed by birds and mammals.

How to control the multiflora rose

To identify the multiflora rose from other wild roses, look for white to pinkish five-petaled flowers, which open in late April to June. Measuring roughly 0.5 to 1.5 inches in diameter, the flowers occur in branched clusters. The leaflets of the plant are dark green and smooth on the upper surface and paler with short hairs on the underside. The base of each leaf stalk bears a pair of fringed stipules, or a small leafy outgrowth, which distinguish multiflora rose from native rose species. Fruits form in clusters during the summer after the flowers bloom, and persist on the plant through the winter as bright red smooth hips, or berries.

For prevention and control a combination of tactics is necessary. Pulling, digging, cutting, and mowing may be viable components of a control strategy. Seedlings may be hand-pulled. Small plants may be removed by digging, ensuring that the entire root crown is extracted to prevent regrowth. Foliar treatments can be applied effectively for a relatively long time since multiflora rose gets an early start by leafing out in late winter and loses its leaves later in the year than many plants. Cutting back the tops to the ground, with six or more cuts per year for two to four years, will weaken the plant, inhibit flower and fruit production, and may eventually kill small infestations. Cutting or mowing before using an herbicide application is usually performed for greater efficacy, as it will stress the plants and increase the herbicide's effectiveness. Because of the long-lived stores of seed in the soil, follow-up treatments are necessary.

A long-term management plan, including continued follow-up maintenance, is critical to prevent re-infestation or new establishment by seeds. Unfortunately, there are virtually no effective predators that feed on or kill multiflora rose. As with many invasive species, spreading awareness and educating others about the negative environmental impacts of multiflora rose, and working diligently through early prevention and rapid response is the most effective way to eradicate the problem. If you have questions or need advice on this or any other invasive species, contact the Master Gardener Hotline at beavermg@psu.edu.

Deanna McCracken is a Penn State Master Gardener in Beaver County.