ANNAPOLIS, MD (May 18, 2006) - Say “everything’s coming up roses” and it is generally a positive statement, unless you
are talking about multiflora roses. Multiflora rose comes up everywhere and is so widespread
and familiar that many do not realize it is a troublesome and costly invasive non-native plant.
Multiflora rose, now the bane of pastures, fence rows and conservation areas, was
brought originally from Asia in the late 1800’s to be used as rootstock for ornamental
roses. In the 1930’s, multiflora rose was promoted as a windbreak for soil conservation
and a living fence for pastures. Still later it was touted as an excellent wildlife
habitat and used as a median and roadside screening plant.
Today it is seen as an out of control invasive which invades untended pastures,
natural areas, and roadsides as well as commercial/ industrial lands. It occurs most
commonly along stream banks, in forests and along forest edges. It takes over with
little benefit to wildlife, while crowding out native plants. Multiflora rose has
been designated a noxious weed in many states, and in Maryland is listed as a public
and common nuisance on land used for agricultural production. In keeping with this,
the Maryland Invasive Species Council has designated multiflora rose as the Invader
of the Month for May.
Multiflora rose is a serious problem in the northeast and midwestern United States,
but can be found throughout the U.S. It can tolerate various soil and moisture conditions
but grows best in sunny, well drained areas. Multiflora rose is a fast grower which can
create dense thickets, preventing sunlight from entering and creating a monoculture.
This growth will replace native shrubs and species.
A member of the rose family, multiflora rose is a perennial densely spreading
shrub which can grow up to 15’ tall. The multiple stems originate from the base,
growing upright, then arching and drooping over toward the ground. Multiflora rose
is a prolific bloomer, blossoming in late May thru June. It has clusters of numerous
white flowers ranging from ½” to 1’ across.
The flowers develop into bright red, small, round fruits called rose hips.
These rose hips can often remain on the plant through the winter, and it is reported
that the seed can remain viable for more than ten years. Humans were the primary
method of spread originally. Now birds and mammals are very effective at moving seed
wherever they go. In fact, germination of the seeds is enhanced by passing through
the digestive tract of birds. Multiflora rose can also multiply by rooting when the
drooping canes rest on the ground.
Control of multiflora rose varies by site, but some basic control principles apply
to all sites. As discussed above, seed is easily moved. But don’t lose hope -multiflora
rose control is possible, even if neighboring or local properties have infestations.
Properly identify the plant before control. Techniques include cultural, mechanical,
biological controls and the use of herbicides. The preferred method will depend on
location and size of the plants. A key control strategy is prevention of spread by
removing plants before the infestation becomes worse. However you chose to remove or
control existing multiflora rose, plan an annual follow up of control treatments
because seed stores are long lived.
Cultural control practices involve promoting the growth of desirable vegetation
to compete with multiflora rose. This is done through maintaining good fertility,
preventing overgrazing, and minimizing soil disturbance.
Mechanical control practices such as mowing or physical removal may be a part
of a control strategy. Unfortunately, frequent repeated mowing or cutting for several
years may be needed in some situations. Mowing may also remove desirable and native plants.
Herbicide control has been the most successful method for controlling multiflora
rose. A variety of effective herbicides are available which can be used along with
different techniques for each for specific situation. It is best to get recommendations
before starting by contacting your County Weed Control Program or the Cooperative
Until recently, multiflora rose grew pest free in Maryland, but now several
biological agents exist, although currently none are completely effective by
themselves. The most common biological control agent of multiflora rose in Maryland
is rose rosette disease, a viral pathogen which is spread by a tiny mite. This
naturally occurring disease, now widespread in Maryland, can weaken and sometimes
kill multiflora rose plants. Symptoms of the disease include development of compact
lateral branches to form “witches brooms” and stunted reddish shoots.
Don’t forget to take time to smell the roses, but stick with roses that are
not as invasive and damaging as multiflora rose.
For more information about other Invasive Species of Concern,
visit www.mdinvasives.org or call the
Maryland Department of Agriculture at 410-841-5920.
photos available electronically on request.