Hi there! I have a 6yo gorgeous Felix Leclerc Explorer Series climbing rose. Last year, mid-summer, it suddenly shot a thick cane out. The flowers and leaves look the same as the rest of the bush, and are not obviously suckers from rootstock. I don’t know if my bush was grafted or not, I know some aren’t.
This spring I see 2 more canes/suckers forming. What causes the canes to form? Is it healthy for my bush? Should I cut them back?
Thank you for contacting the Toronto Master gardeners concerning your Felix Leclerc Explorer Series climbing rose.
Back in the day most roses that were available were grafted roses. This would include the hybrid tea, grandiflora and floribunda roses and David Austin Rose. As demand for hardier roses increased Agriculture Canada developed a series of cold tolerant roses, namely the Explorer series. The Explorer, Parkland, Canadian Artists and new 49th Parallel series, are all hardy roses bred for our cold climate and are almost always sold growing on their own roots, see The Canadian Bred Roses: The Explorers and Parkland for more information on the different hybrids available.
To tell the difference between the grafted and own root rose you need to look near the base. A grafted rose will have a knot like structure (buldge) near the base where the graft was made and the canes will grow from this buldge. A root on its own root will send up canes directly from the root system. The Laidback Gardener’s blog on Cold Climate Gardeners: Stick to Own Roses has an excellent diagram illustrating a grafted rose.
Climbing roses put out two types shoots, the main structural canes and the flowering shoots/branches, which grow from the structural canes. The structural canes are the ones that need to be tied or woven into a support structure. It sounds as if your rose is sending upp more support canes. Garden Making has an excellent article on How to Prune Roses which describes the best way to make a pruning cut, and how to shape a climbing rose.
Good Luck with your rose.