By Carolyn Lorié
Multiflora rose is not without charm; in fact, there was a time when people went out of their way to plant it. The pretty spring flowers have a sweet scent; birds nest in the sturdy branches and eat the berries. You might even catch a glimpse of a bear or snowshoe hare gnawing on the twigs and bark.
But the human love affair with the plant ended some time ago, and with good reason. In addition to fragrant flowers and berries for the birds, multiflora rose has another attribute: it spreads voraciously and chokes out native species. The U.S. Natural Resource Conservation Commission (NRCS) lists multiflora rose as a noxious weed in a number of states, including all of New England.
Multiflora rose (Rosa multiflora) is native to Japan and was introduced to the United States in the nineteenth century, originally as rootstock for ornamental roses. Like many introduced species, it was once touted for both its beauty and its usefulness. It was widely planted in the first half of the 20th century as a living fence for livestock and also for erosion control.
According to Matt Tarr, associate professor at the University of New Hampshire Cooperative Extension, the U.S. Department of Agriculture used to pay landowners to plant multiflora rose on their property as a habitat improvement. Now they pay landowners to eradicate, or at least manage, these plants.
The level of infestation varies across New Hampshire and Vermont, but as a general rule is worse the farther south you go. “Multiflora rose is on the unofficial watch list of invasive species for Vermont,” said Elizabeth Spinney, invasive plant coordinator for the Vermont Department of Forests, Parks, and Recreation. “We can look to our southerly neighbors to see that multiflora takes over field habitat and creates barriers along woodland edges for wildlife that go from field to forest.”
Windsor County Forester Jon Bouton said he hasn’t seen enough of the plant to worry him, but he wants to keep it that way, so he knows exactly where in his territory the rose bush has become prolific. “Multiflora rose is a really nasty invader,” he said. “It takes a while to build up some critical mass of colony and seed production capacity, but when it reaches that threshold of being in the way or a nuisance, it is nearly impenetrable.”
The best way to get rid of it without using chemicals, said Bouton, is to yank it out with cable and a tractor. The problem is that the canes have talon-like thorns that “really grab you.” You can mow it, but will have to do so for several years and even then there is no guarantee it will not reappear.
Not only is it difficult to remove, but a single plant can produce hundreds of thousands of seeds in a single season, said Spinney. Given the number of bird species that feed on the berries, the seeds can be widely disseminated. And once they are in the soil, they can stay viable for up to two decades. Even without the birds, multiflora rose can spread. If any of its long, arching canes touch the ground, they can take root and a whole new bush crops up. Once a thicket forms, it quickly takes over and less vigorous, native plants can’t compete.
Landowners who want to replace this invasive plant should do so with a native rose, said Bouton. They too provide flowers, food, and refuge for wildlife, but do so without the hefty toll of multiflora rose.
Carolyn Lorié lives with her rescue dog and very large cat in Thetford, Vermont. The illustration for this column was drawn by Adelaide Tyrol. The Outside Story is assigned and edited by Northern Woodlands magazine and sponsored by the Wellborn Ecology Fund of New Hampshire Charitable Foundation: firstname.lastname@example.org.