Background/Question/Methods Rosa multiflora, a semi-evergreen woody perennial shrub, is a noxious weed introduced from eastern Asia. Its widespread distribution across North America is due to its use as living fences, soil erosion control, wildlife cover, and rootstock for cultivated roses. Herbicide treatments are a common control method, yet impose potential risks to native flora. We surveyed the distribution and abundance of multiflora roses in an 8ha portion of the Chance Creek Preserve (Lorain County, OH), which revealed the non-random distribution of plants and the non-random distribution of flowering (p<0.01). We selected six sites (3 flowering and 3 non-flowering) for testing four treatment methods duplicated per site: “cut-only”; “cut-treat”; “cut-cover”; “cut-treat-cover” in October 2019. We used the herbicide glyphosate as “treat” and black weed fabric as “cover”. We also measured differences in soil moisture and percent open canopy among the six sites. We surveyed for regrowth in June and October 2020. Since both light and herbicide can limit plant growth, we predicted that “cut-treat-cover” would be the most effective control method. We were particularly interested in comparing the “cut-treat” and “cut-cover” treatments with “cut-treat-cover,” especially since “cut-cover” is the more environmentally friendly method. Results/Conclusions All four treatments significantly reduced cane growth at the June survey, but by the end of a full growing season, the data partially supported our prediction, as “cut-treat-cover” significantly reduced cane growth (p=0.0018). However, this reduction was matched by the “cut-cover” method (p=0.0019). In contrast, the “cut-treat” method, while significant, was less effective (p=0.02) and the “cut-only” method was insufficient (p=0.28) for controlling regrowth. The flowering sites had significantly more open canopy (p=1.4x10-6) and were significantly wetter (p=0.006). Open canopies and high soil moisture correspond with the high loss of ash trees due to the Emerald Ash Borer, which correlates with increased multiflora rose success in the preserve. The “cut-cover” treatment appears to offer a viable control method that is more effective than herbicide treatment alone and without the risks to native flora or selection for herbicide resistance. Since we could find no evidence in the literature reporting using “cut-cover” to control multiflora rose, we believe this method should be tested for its effectiveness on larger temporal and spatial scales.
