People love roses, be it for their attractive appearances or their sweet scents. It is thus quite a common practice to have these plants in hedges, gardens, bouquets, and other decorative spaces. People dedicate acres and acres of land to grow these species in the hope of turning a good profit from their sale. Thus coming across the Multiflora Rose could ignite such thoughts, isn’t that right? Well, as much as this rose may be pleasing to the eye, it might not be the best rose for in your yard, and in this guide we will talk about how to control Multiflora rose.
The Multiflora Rose is a wild plant, that can spread over a large area within a short time. It forms thorny thickets which prove impenetrable to humans and animals. These bushes are quite big, and they can take over wastelands and pasture lands. One year, animals have plenty of space to graze, and the next, they barely have enough to eat owing to the invasion. What’s worse, these thickets provide breeding grounds for pests such as rats.
These bushes produce tons of seeds each year, and this aids in their distribution. The Multiflora rose also invades natural habitats and damages them in the process, taking over and displacing the native species. As things stand, this species has taken over more than forty million hectares on the eastern side of the United States.
That is land which could have gone to other uses; land people are busy trying to reclaim, land which could have been saved if early interventions were in place. Not only has this economically affected the country, but also environmentally. For this reason, they fall under the classification of noxious weeds in the United States. Interestingly, this plant has not been as problematic in areas outside the United States.
Fun Fact
The introduction of the Multiflora Rose was a means to propagate rose hybrids and stabilize soil in erosion-prone regions.
How to Identify the Multiflora Rose
The Multiflora Rose is a sprawling thorny perennial shrub that features small clusters of white flowers. When in the ideal conditions, it can grow as high as fifteen feet. Older plants have multiple stems that spread both outwards and upwards. They increase in number over time and create dense thickets that are hard to penetrate.
Their stems are long and flexible, and their colors vary from red to green. They feature stiff and sharp thorns that curve towards the outside. The thorns have broad bases and occur in twos.
Rosa multiflora bark
The leaves of this shrub appear in alternating positions and have a compound appearance. That is, the stem is central and surrounded by leaflets in twos. Leaves vary in sizes and have about five to eleven oval leaflets, each measuring about one inch. On the edges of the leaflets is teething. Under the leaflets are some hairs which make the underside appear paler than the upper side.
Rosa multiflora leaves
This shrub produces tons of white flowers that appear in clusters. However, in some cases, you will find that the flowers are pink. The flowers measure about one half to one inch, and they have five petals each. Blossoming takes place between May and June.
In the hot months, the flowers give rise to small, rounded, and hard fruits, which measure about a quarter an inch. The fruits remain on the plants during the cold months. Inside are yellowish seeds which can remain viable for two decades in the soil.
Multiflora Rose hips
This shrub relies on a fibrous root system.
If you see a shrub that meets the above description, you could be dealing with the Multiflora Rose.
Look-Alikes
The Multiflora Rose is similar to other rose varieties. Examples include the pasture rose, the smooth rose, and the prairie rose, amongst other native species. The difference lies in the hue of the flowers, as native flowers have pink clusters. Also, native species lack fringed stipules at the bases of their leaves, which is a characteristic of the Multiflora Rose.
Where did Multiflora Rose come from?
Where did this beautiful rose species originate? Like most invasive species, it is not native to the United States, but rather East Asia. It has since spread to other regions owing to intentional introduction. Some of these regions include North America, South Africa, Pakistan, Australia, and New Zealand.
You will now find this species on the eastern side of the United States as well as on the West Coast. At present, it takes up more than forty-five million hectares of land on the eastern side. The affected areas are savannas, open woodlands, roadsides, old fields and pastures, forest edges and trails, pastures, and other such areas. Even dense forests are not safe from the invasion of this plant. Where a canopy opens up, the Multiflora Rose moves in, fast.
Towards the start of the twentieth century, there were concerns as to soil erosion, and people sought means through which they could deal with the issue. In doing so, conservationists championed the use of the Multiflora Rose in the wild and hedges.
People used the Multiflora Rose as a rootstock on which other rose species could grow. Over time, it became clear that this species was a threat to native plants. What’s more, its distribution took place at a fast rate and spread to other populations in the form of escapes. Repeated introductions thus took place over time.
Using this species as a way to control soil erosion has proven to lead to other problems. As such, it is no longer in use in horticulture, and you will not find it in nurseries.
Where does Multiflora Rose grow?
The habitat of the Multiflora Rose will depend on the area in question. In its native regions, it grows amongst other shrubs in slopes and along rivers. It grows in altitudes ranging from 300 to 2000 meters above sea level. It does exceptionally well as it can adapt to hilly places where erosion would otherwise threaten its growth. Plus, it can do well in varying soil conditions. However, you will not find it in arid areas as well as places where the water is stagnant. It helps to note that though it can withstand cold climates, it has a hard time surviving the cold winters that are characteristic of the northern states.
In areas where it is not native, you will find it in diverse places, ranging from old fields to forest edges through to stream banks. It is not unusual to see it growing in abandoned pastoral lands and dense forests. Where it becomes naturalized, it does well in places with well-draining soil and lots of access to sunlight.
This species does best in deep and fertile soil with good drainage. Where there is erosion in play, it might not thrive as well as it would in the ideal conditions. It helps to note that though this species was brought in to deal with erosion, it cannot grow well in eroded areas. Where an area lacks topsoil, and the subsoil is of poor quality, growing this species would be a hurdle, even with fertilizers in play.
Reports of Multiflora Rose in the US
How does it reproduce?
When canes of the Multiflora Rose touch the ground, roots sprout, and from these comes a stem. This form of reproduction leads to the spread of this species. Other than this vegetative propagation, this species also spreads through the dispersion of seeds.
Take North America as an example. Flowering starts towards the end of May or start of June. As this happens, pollination also begins, mainly through insects. The flowers produce tons of sweet-tasting pollens. And given that the flowers occur in the tunes of hundreds, insects have a lot of food. The most common pollinators are the honey bees and hoverflies.
The Multiflora Rose seeds can remain in the soil for at least two decades while maintaining their viability. Couple this with their ease of dispersion, and getting rid of this plant would be quite hard. The bushes can thus exist indefinitely as there would be young plants to take the place of the old.
Dispersal Methods
Non-Biotic
A common means of dispersal is the falling of seeds from the parent plant to the ground. If the conditions are ideal, the seeds sprout and give rise to new bushes. Other than this, the stem tips can root when they touch the ground, further encouraging the spread of this bush.
Biotic
Lots of birds feed on the rose hips in the winter and the fall. A good example would be robins. Chipmunks, wild turkeys, and black bears, amongst other animals, also feed on the rose hips. As the seeds move through the digestive tracts, they do not break down. Instead, the digestion process promotes their germination, and once they are in ideal soil conditions, they sprout.
Dispersal by animals can also take place by accident. If the Multiflora Rose is in an area where birds like to perch, they will carry the pollen through a wide area.
By Intent
This species has widely been of use as a rootstock. It was also useful in stabilizing soil and forming beautiful hedges. Its introduction to countries such as New Zealand has taken place for many decades.
Threats of the Multiflora Rose
What can this plant do to or for the environment? Well, this species can spread over a wide area within a short time. In doing so, it forms thickets that are hard to penetrate. Humans and animals, therefore, find a hard time accessing pasturelands as well as recreational areas. It does not help that this plant can adapt to tons of habitats. As it takes over an area, it pushes out the native plants and affects the ecosystem.
Economically, this plant will take over pasturelands and reduce grazing spaces. When cattle and other animals get exposed to this bush, they can get irritated, which adds up to the veterinary costs. Also, the species pushes out native plants, and this affects the agricultural productivity of a given area.
Environmentally, this plant adapts to tons of habitats, which makes it a threat to native species. Where gaps in forests occur, this species can grow. However, it cannot take over a forest as it would get shaded out by tall trees and would thus not reach its potential. But in savannas and open areas, it can push out the native vegetation.
Can you use it?
What are the uses of the Multiflora Rose? The good news is that it is not all bad and has proven to be of use to the economy, environment, and society.
Economically, it was of use as a rootstock, which enabled people to grow tons of grafted roses. You can think of this plant as a parent to many rose hybrids you hold dear to your heart. Towards the start of the twentieth century, using this shrub to stabilize soil was a norm. Soil conservationists embraced its use for this. They also adopted it as an ideal hedge. Though its use in the United States has reduced, it is a popular rootstock option in areas with cold climates and neutral/ acidic soils.
Socially, people have used rose hips as preservatives and herbal remedies. The hips have tons of minerals and vitamins, alongside bio-active compounds. Additionally, they are a good source of essential fatty studies, which have made them the subject of research regarding their cancer growth-fighting abilities.
They are not only of use internally, but also externally. You can crush the leaves and use them on sores as a means to alleviate the pain and fight infections. Hedges of this shrub are useful along busy roads where they can act as crash barriers. They can also reduce headlight glares and make driving at night much more comfortable.
How does the environment benefit? When this plant is not busy pushing out native species, it is providing food to birds and animals. The rose hips are a good source of nutrition. Also, the bushes serve as shelter to animals.
So this plant is not all bad. However, leaving it to grow without any means of control can lead to it taking over more land than it already has. It is, therefore, essential to take measures to get rid of unwanted Multiflora Rose plants.
How to control Multiflora Rose
The Multiflora Rose has been a blessing to horticulturalists. Thanks to it, we now have many rose hybrids that couldn’t have existed without its rootstock. However, that does not negate its adverse impacts. There is thus a need to control multiflora rose.
Prevention
It is always best to avoid a bad situation, where possible. And in the case of the Multiflora Rose, you can have the upper hand where you take early measures to control its growth. When you see some plants matching its description around your home, be sure to identify them. If they turn out to be Multiflora Rose, you need to eliminate them immediately. Doing this will ensure that they do not mature and do not seed. Without seeds, they cannot spread, and the neighborhood will be free of invasion.
Where you notice new seedlings coming up at a fast rate, you can choose to combat their growth by the use of ground cover. Some grasses are very competitive and will take over the outdoors, giving little chance of survival to the bushes. When plants establish, ensure that you deal with them before they get the chance to fruit.
You should also choose species that would work for your climate as these would be more effective in fighting off the Multiflora Rose. Additionally, ensure that you mow regularly to prevent the sprouting of new seedlings. And finally, choose fertilizers that will not encourage the growth of this invasive species.
If you do all this and you still have a problem on your hands, here is what you should do:
Mechanical Control
You should note that the Multiflora Rose has a vigorous fibrous root system that spreads with ease. Thus, if you choose to get rid of the plant by burning, you will not get to the roots. As such, you will only hit pause to its growth as it will sprout again.
The same goes for clipping. However, continued cutting has proven to be effective to control multiflora rose. Where you have an established bush, start by clipping the plant to a height of seven and a half centimeters twice each month during the growing season. It will take about two years to kill the plant finally. But the good thing is that you can avoid using chemicals which can harm desirable plants.
At the seedling stage, keep at the mowing for at least two years. If you want fast results, you can add chemicals to the process.
You could also pull out the bushes. Note, though, that you should exercise caution when doing so as these plants are thorny. It is best to use machinery for this process. As you pull out the plants, ensure that you get all the roots out of the soil. Leaving fragments increases the chances of re-sprouting, and you would face new growth within the year. After successful removal, keep an eye on the area as there could be re-sprouts. If any occur, deal with them immediately.
Biological Control
The rose rosette disease is your best bet in fighting the spread of the Multiflora Rose. However, the American Rose Society has raised concerns as to its suitability.
Chemical Control
Cut Stem treatment is an effective way of dealing with established bushes. There are tons of herbicides that you can use. It depends on the scale of work as well as the environment in which you live. Start by cutting the plant as near to the ground surface as is possible. Mix the herbicide as directed by the manufacturer and apply it on the cut stem.
Alternatively, you could use a basal bark application by directing the mix towards the lower sections of the stem. Basal bark treatment works best in the winter. For both of these methods, effectiveness is more when the bush is large with few stems. The good thing about this control method is that you will avoid damage to desirable plants. Plus, it ensures that the cut stem does not re-sprout.
When using the Cut stem or Basal bark method, apply a 25% solution of glyphosate or triclopyr mixed in water to the cut stump surface, making sure to cover the entire surface.
The other chemical means is a foliar application. As is the case with the cut-stem treatments, there are many herbicide choices. Most of these herbicides work best when applied in spring. Apply a 2% solution of glyphosate or triclopyr and water plus a 0.5% non-ionic surfactant.
In all these cases, consider the effects of the chemicals on nearby vegetation.
Utilization
Did you know that you could forego the above means of control by relying on animals? Where the bushes are in their early stages, you can let goats and sheep graze in the area. The animals will feed on the new buds, shoots, and leaves, preventing the bushes from spreading. In a few seasons, the bushes will be as good as gone. And you will not have to spend money on chemicals. Where the shrubs are invading pasturelands, you can use goats as they have been known to control prickly plants.
Conclusion
There hasn’t been much research on the ecology of the Multiflora Rose. As such, there are many gaps as to its limitations and interactions with native species. Information on its habitat needs is also limited, which makes zeroing in on its weaknesses hard. However, people have more than enough to go on when fighting this species.
We cannot change the past, but we can work on safeguarding the future by dealing with the menace that this species currently presents. And with that out of the way, our ecological system can maintain some balance.
All the best!
References
Invasive Species Biology, Control, and Research Part 2: Multiflora Rose (Rosa multiflora) – https://apps.dtic.mil/dtic/tr/fulltext/u2/a492988.pdf
Multiflora Rose Best Management Practices – https://www.ontarioinvasiveplants.ca/wp-content/uploads/2018/05/OIPC_BMP_Multiflora_Mar122018_D5_WEB-1.pdf
Rosa multiflora (multiflora rose) – https://www.cabi.org/isc/datasheet/47824
Global invasive species database – http://www.iucngisd.org/gisd/species.php?sc=215
SPECIES: Rosa multiflora – https://www.fs.fed.us/database/feis/plants/shrub/rosmul/all.html
