– Christine Gelley, Agriculture and Natural Resources Educator, Noble County OSU Extension
If not already, these bloom will soon be common site throughout Ohio!
Mutiflora rose is reaching full-bloom this week. The sweet aroma of roses and honeysuckle drifting through the June evening air is almost heavenly when paired with the scent of freshly mowed hay. As sweet as they smell, both multiflora roses and Japanese honeysuckle are invasive weeds commonly found in Ohio pastures and woodlands.
I tend to be less critical of these two weeds than many others simply because they are not poisonous to livestock, they can provide some benefit to wildlife (primarily birds and insects), and they can be target grazed with small ruminant animals. Goats are quite effective grazers of both roses and honeysuckle because they have a specialized prehensile lip that allows them to select individual leaves from plants and avoid thorns and woody tissue.
However, NO ONE should be propagating these plants on purpose or ignoring them in the landscape. Because they have invasive status in Ohio, it is every landowners’ legal responsibility to control their spread.
Interestingly, both multiflora rose and Japanese honeysuckle were introduced to the Eastern United States from Asia in the 1800s for ornamental use. Multiflora rose originally used as a rootstock for other rose species and then was promoted for erosion control and as living fence in the early 1900s, but it was so aggressive in our landscape that it became increasingly difficult to manage as the years passed. Today it is considered a noxious weed. Japanese honeysuckle was imported for its beauty and fragrance, but soon escaped private landscapes and naturalized itself all along the East Coast smothering many native plants along the way with its fast-growing vines.
Multiflora rose is one of our weeds that can be treated successfully with a foliar herbicide while in bloom. However, it is best to avoid spraying herbicides directly on blooms that attract pollinators, so proceed with caution when selecting a herbicide and a spray time. This is a concern with multiflora rose because to achieve effective herbicide response, you need to fully coat rose leaves with herbicide, and inevitably the blooms will be sprayed too. Pollinators tend to forage very little in the hour before sunset and the two hours prior to sunrise, so evening time would be ideal for a foliar herbicide application if the plants are in bloom.
To make control easier from a timing perspective, make an effort to spray rose plants before they bloom or after the petals have dropped. If you have a plethora of multiflora rose, you should be able to identify it now and create a plan to address it.
Multiple herbicides provide good control of multiflora rose if the plants are small. These include products containing metsulfuron methyl, dicamba, 2,4-D, triclopyr, and/or glyphosate. The best herbicide for your situation will depend on the time of year, the application method, the setting where it grows, the size of the plant, and label restrictions of the herbicide, which may include lactation or slaughter withdrawals for livestock and/or hay harvest restrictions.
Multiflora rose can also be treated in the off season through basal bark or cut stump treatments, but these methods may be more labor intensive than foliar applications. Although they require more physical labor, they are often more effective on large plants or patches of many roses due to the direct approach of treating the stem tissue and sending translocated herbicides down to the roots.
Multiflora rose often takes multiple years and methods to achieve measurable control because it is a perennial that can easily spread by stolons, sprout from root tissue left behind in the soil, and seed can lay dormant in the soil for up to 20 years and still be viable. One well-established plant can produce 500,000 seeds, which are often spread by birds and deer that feed on rose hips. Unfortunately, mowing multiflora rose has limited effectiveness. It can be good control on small plants that are newly emerged. Mechanical or cultural control of larger plants will require pulling or digging of the root tissue.
There are many reasons why we see it everywhere. It is a thorn in many a manager’s side. Diligence and patience are key in gaining ground back from a multiflora rose infestation. My advice to you is enjoy the blooms today but bid those plants goodbye in the coming weeks.