Multiflora Rose can grow as tall as 10-15 feet—forming dense thickets in unmanaged areas such as fields or forest edges and can even be found climbing up trees!
Commonly known as multiflora rose, Rosa multiflora is a rapidly growing, deciduous climbing and rambling shrub in the Rosaceae family. Native to China, Japan, and Korea. It is now commonplace to see this space invader in both urban and rural wild areas; their bright green and red stems are noticeable along many roadways, and their blood-inducing thorns are a defense mechanism of which to be wary!
The plant was originally introduced to the United States during the 1860s from Asia as rootstock for ornamental rose breeding programs. Its popularity grew at the turn of the 20th century and was widely used throughout the Midwest and the Northeastern United States as a solution to control erosion, as habitat and/or a food source for wildlife. It was used as a living fence for pasture-raised farm animals and was even encouraged to be used in highway medians to serve as a crash barrier and to reduce the glare from oncoming traffic.
There are multiple traits by which we can consider multiflora rose an invasive species, including the high numbers of seed produced and how long seed can remain viable. As many as 500,000 seeds may come from a single plant in one growing year (Munger, 2002)?
It is easy to imagine how such a widely planted species, which has now escaped cultivation beyond what many states deem ‘controllable,' has turned into a real problem in the landscape and has therefore been classified as a noxious weed across most of the country.! Seeds can stay viable in the soil for up to 20 years, depending on soil conditions. Even further, while most seeds fall close to the parent shrub, birds and other berry-feeding animals can disperse the seed great distances without much trouble.
Multiflora rose also has an incredibly effective reproductive strategy: it can replicate itself both by sexual and asexual means. Both male and female reproductive parts are consolidated into the same flower on the same plant (known as monoecious); hence, one plant can easily turn into many, which is why dense thickets form quickly. They also reproduce asexually, both from vegetative sprouts which can form when stems are cut or broken, and easily take root. Sometimes these new sprouts can even produce more flowers (hence, more fruit and seeds) than the original parent stems! To top it all off, most native trees and shrubs lose their leaves earlier in the fall and leaf out later in the spring than multiflora rose. This gives it an advantage over native plants because it is photosynthesizing and reproducing for longer periods of time.
Many wonder how to distinguish multiflora rose from the native Carolina (or pasture) rose. Here are some bullet points to remember:
The blooms on the native Carolina rose (Rosa carolina) are pink, are non-clustered and occur from June to July – multiflora rose has clusters of white flowers that occur from May until June.
The thorns on Carolina rose are straight, whereas multiflora rose has curved (or cat claw) thorns.
The next question is: Now that you know you have multiflora rose on your property, what do you do?
There are multiple methods by which this noxious weed can be controlled, although complete eradication can be quite difficult. Understanding the degree to which your landscape has been invaded is the first step in addressing the problem. If the population is young and small, hand-pulling could do the trick. However, this is rarely the case. Brush mowers can be used to cut larger infestations, but while this method will weaken plants, it will still not eliminate them. Resprouting could also likely occur from the cut-up root stalks.
Some folks have attempted to utilize goats in the removal of multiflora rose, which would have similar effects as the brush mower but by far more adorable means. If cutting the shrubs down isn't doing the trick, and you haven't been able to wrangle a herd of goats, the next step may be to apply a form of herbicide to your multiflora rose population.
The options would be to:
1. Apply on the foliage while leaves are actively growing, or
2. Cut the stump down to about an inch from the ground and then immediately apply glyphosate to the freshly cut wood, using a paint brush or sponge (or for a greener option, you could try 30% horticultural vinegar!
The PVC Herbicide Wand, is a device that can be made using directions from The Nature Conservancy. You pour herbicide into the top of the wand, and it comes out the bottom. The red valve controls the level to which the liquid comes out and soaks a sponge at the bottom of the wand. This ensures complete, precise coverage of the freshly cut stump of multiflora rose, avoiding contact with surrounding plants. Remember, the label is the law when it comes to using the correct amount of herbicide!
There are two ideal times to apply herbicide to multiflora rose: once in the late summer before the berries mature and get dispersed (July to mid-September), and again in the dormancy period (November through February). The dormancy period is a fantastic time if you want to take some of the guesswork out of identifying the plants. Multiflora rose are often easily spotted later into the winter because they hold on to their leaves longer than most native trees and shrubs.
Sources:
Center for Invasive Species and Ecosystem Health, https://www.invasive.org
Munger, Gregory T. 2002. Rosa multiflora. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available:
https://www.fs.usda.gov/database/feis/plants/shrub/rosmul/all.html
[2022, June 25].
TNC Global Invasive Species Team Page, https://www.invasive.org/gist/tools/wand.html
Wenning, B., 2012. Multiflora Rose: An Exotic Invasive Plant Fact Sheet, ecolandscaping.org. https://www.ecolandscaping.org/07/landscape-challenges/invasive-plants/multiflora-rose-an-exotic-invasive-plant-fact-sheet/