Taking the mystery out of pruning clematis

Most gardeners will agree that the clematis is a fantastic vine that produces months of beautiful flowers. So why do many gardener’s shy away from adding this spectacular vine and its many choices of colours to their garden? It amounts to the simple reason that many gardeners are confused or intimidated by the fact that a clematis needs to be pruned. This column will hopefully demystify how and when to prune your clematis.
Clematis can be divided in to three distinct groups.
Group 1: The alpine (Clematis alpine), big petal (Clematis macropetala) and golden clematis (Clematis tangutica) vines belong in this group. These varieties flower early in the spring entirely off of last season’s growth.
Group one requires very little attention and for the most part are never pruned. The only trimming that may be needed is to remove a dead or broken branch.
Group 2: This group can be a bit tricky to determine when and how to prune. This group of clematis flower on new wood produced directly from last year’s growth. Therefore you should not over trim but only lightly trim in order to promote branching.
By early May just after leaf-out you should see the flower buds in the leaf axil (where the leaf connects to the branch) starting to swell.
Because this group of clematis flowers early in the season, it will only be a week or so before the flower emerges from the swollen bud.
Prune the stem only back to just above the last pair of these swelling buds. This will be just a short piece that you trim off and you do not need to trim every branch.
Many clematis with double flowers belong in this group as well as hybrids like “Niobe,” Artic Queen, Anna Louise, “Blue Moon” and “Snow Queen.”
Group 3: The general “rule of thumb” is if the first flowers appear later into the season (July until fall) then the clematis variety usually falls into this group.
The reason for the later flowering schedule is because these varieties flower on new wood, often grown right from the ground or the first 1-2 feet of the base of the plant each year.
In the spring between mid-April and the first of May you can remove all of the old wood, which will appear brown and dry right back to just above the last set of swelling buds that you may find near the base of the plant.
If you do not locate any live buds in the leaf axils or green wood in the lower part of the plant then cut back to about 4 inches above ground level. Many of the varieties found that are hardy for our region will be called “Clematis viticella” or are among the other hybrids like “Jackmanii” (the common dark purple one many gardeners in the area have), “Ramona,” “Josephine,” “Nelly Moser,” “Ville de Lyon,” “Durandii,” “Polish Spirit” (dark purple and very hardy) and “Purpurea Plena Elegans,” and many more.
If you are in doubt about which group your variety falls within or are not sure which variety of clematis you have treat your clematis as if it belongs in Group #2.
If after a few growing seasons you are sure your clematis is a late flowering variety and you can obvious locate a large abundance of dead wood each spring then you can treat your variety like a Group #3 variety.
It never hurts to be on the cautious side when pruning your clematis as you can always prune more away but you cannot add it once it is gone.
I hope that this information has helped to dispel your fears about growing and maintaining a clematis in your own garden.
Join the many gardeners that already have this beautiful vine growing in their garden and plant one today.