What a pleasure to share a Guest Post by Bev Werbowy. A talented gardener and long-time member of the Thunder Bay Horticultural Society, Bev is known for her interest in alpine plants, rocks and the interplay of plant textures and hues. Her sweetly compact city garden was part of the 2015 Thunder Bay Art Gallery Garden Tour.
This article first appeared in the Spring 2016 issue of Bay Leaves, the Thunder Bay Horticultural Society newsletter. You may want to keep this post for reference. Republished with permission.
Thank you, Bev.
Why are we seeing the same clematis varieties year after year?
Why are so many offered which are not guaranteed to survive in our Zone 3 gardens?
We have all, at some time, been seduced by those stunning large-flowered hybrids, resplendent in their jewel-toned hues, only to witness their inevitable decline in later years.
A knowledge of the specific pruning needs of the many species of Clematis will determine which we should plant and which we should avoid. The genus Clematis can be divided into 3 distinct groups based on the aforementioned pruning requirements. They are generally referred to as Group A (Group 1), Group B (Group 2) and Group C (Group 3).
Group A (1) Clematis
Notable Clematis alpina cultivars
Notable Clematis macropetala cultivars
- large-flowered hybrids, single and double
- bloom in early summer and occasionally re-bloom in late summer
- flower on previous year's growth
- 'Duchess of Edinborouqh'
- 'Multi Blue'
- 'Dr. Ruppel'
- 'The President'
- 'Elsa Spath'
- 'Nelly Moser'
- 'H.F. Young'
Group C (3) Clematis
The Clematis viticella hybrids, also members of Group C (3), perform reliably in Zone 3. What they may lack in flower size, they more than make up for by their profusion of bloom. Their flowers come in a variety of forms; open-faced, bell-shaped, rosette and recurvate, They will happily clothe a trellis or scramble through shrubs.
'Polish Spirit' is one of a group of hybrids bred by Brother Stefan Franczak, a Jesuit priest from Warsaw. Other notable examples of Polish Clematis in Group C (3) are 'Warsaw Nike', 'Danuta' and 'Kordynol Wyszyriski'.
Mention should also be made of Clematis integrifolia 'Arabella'. Purple-blue, this plant is very vigorous, a great scrambler.
Clematis recta 'Purpurea' – a herbaceous clematis whose leaves emerge sporting a lovely purple-burgundy colour. They will retain this hue until the small white flower clusters emerge. I train this plant up a small
obelisk, thereby providing a striking exclamation point in the perennial border.
The well-known Clematis tangutica is a prolific climber (up to 4m). It produces small yellow, cup-shaped flowers.
Final thoughts ...
Check the pruning group before purchasing. lf it's not on the tag, Google the cultivar first.
Avoid Group B (2). • lf you must succumb to Group B envy, try 'Guernsey Cream'. lt has survived in my garden for five years ... by keeping my fingers crossed (and the ground mulched)!
Most of the cultivars mentioned are profiled on the Royal Horticultural Society online plant guide. It is an excellent compendium of plant information, but always confirm the Canadian hardiness of plants to be sure of success in our colder zone.