Multiflora Rose in Point Pleasant Park, HalifaxPosted 11 July 2016 | Updated 16 July 2016
More tracks & sites added 20 July 2016.
Google Photos Link: https://goo.gl/photos/xj1y96qbYjcGaCCW6
Rosa multiflora is not amongst the invasive species cited in the PPP Management Plan
in 2008, but now has a significant foothold in the park.
This documentation of Rosa multiflora in Point Pleasant Park was conducted in relation to a motion passed at Halifax & West Community Council on June 28, 2016:
I had highlighted this issue earler for Waye Mason, the councillor for the District 7 and a member of the Point Pleasant Park Advisory Committee.
On Monday July 11, 2016, I surveyed approx 3.5 km of roads and trails. Rosa multiflora was just at or just past peak flowering and easy to spot. I found it at 23 sites. On July 14 and 15, I surveyed an additional approx 2.5 km and found it at 14 sites, and a few shorter routes on July 18 and 20. Some sites have more than 1 plant or clump but they are in close proximity. I have undoubtedly missed a few.
Overall Rosa multiflora is more numerous on outer roads or trails than deeper into the park, and there are concentrations at particular sites that have large open areas such as at Fort Ogilve and the Cambridge Battery and on Cable Road down to the pumping station. Paths which are narrow and quite closed have few or none. Jeremy Lunholme says that there has been R. multiflora by the pumping station for some time. That site could well be the initial nucleus for spread of R. multiflora.
Overall there are many more plants than I had expected based on casual observations over the last several years, and there are a few areas with exceptionally high concentrations, most notably at Fort Ogilve. It would clearly be more work to cut back existing plants than I had suggested might be the case before conducting the survey. (View Letter)
I believe R. multiflora in PPP could still be controlled at this point. If concentrated efforts to do so have to delayed, existing plants should be cut back ASAP so that they are not allowed to fruit (or if fruit has set, so that fruit does not mature) which will reduce dissemination by birds. Many of the existing plants are growing aggressively and will be much more difficult to cut back in another year.
My suggestion is to cut all plants back by the end of July to stop them producing fruit. I suggest doing this before the end of July as possible because they are highly visible right now and while some fruits have set, they are not mature. Ideally plants would be cut back and the roots dug or pulled out (with mechanical help) and/or glyphosate applied to cut bases of the plant (only to the base, not to the surrounding soil). However, simply cutting them back now will stop the production of fruit and the complete removal could be conducted later, e.g. in September. (Please consult professional horticulturalist or an invasive plant specialists for details about use of glyphosate.)
Those are my thoughts. Please discuss strategies with Peter Duinker, Jeremy Lundholm (both of whom have been involved in management and/or research on PPP vegetation) and others as well.
For each site I prepared a short video and photos which I have posted on Google photos. You may have to sign in as a Google User. When you open the first photo, click on the "i" (information) symbol at the top right and it will bring up information about the photo to the right, including for most photos the location in Google Maps. Those locations could be off 10 m+; the GPX for waypoints obtained with a Garmin GPS should give the locations with more accuracy. Download GPX files with waypoints: WP 1-29 and WP 31-46 and WP 49, 50 (ignore #48).
Please e-mail me (davidgpatriquinATyahoo.ca) or call me at 902-4235716 if you have questions or want to talk to me. Please put "Multiflora Rose PPP" in the subject line.
July 11, 2016
Updated 20 July 2016; survey completed.
On behalf of the Nova Scotia Wild Flora Society
and the Halifax Field Naturalists