Vigorous Himalayan deciduous clematis with masses of small white or pink four-petalled flowers smothering the plant in late spring. The earliest and most reliably free-flowering of the large clematis species.
Hardiness ratings
| System | Rating | Temperature range | How to read it |
|---|---|---|---|
| USDA hardiness zone | Zone 6–9 | −23.3 °C to −1.1 °C | Plant tolerates down to this zone |
| RHS hardiness rating | H5 | −15 °C to −10 °C | Plant needs at least this level of cold tolerance |
| Canadian plant hardiness zone | Zone 6–8 | −18 °C to −1 °C | Plant tolerates down to this zone |
| Australian (ANBG) zone | Zone 2–6 | −10 °C to 15 °C | Plant tolerates down to this zone |
About Mountain clematis
Clematis are unusual among climbers in that they climb by twisting their leaf stalks around supports rather than by tendrils, twining stems or adhesive pads — which is why they need something thin enough to grip and will not climb a bare wall. Their pruning is governed entirely by when they flower, and the standard three-group system exists for that reason: species that flower on the previous year's wood are cut back after flowering, while those flowering on new growth are cut hard in late winter. Roots prefer cool, shaded ground while the top grows into light.
Growing notes
- Plant against a large wall, tree, or pergola — vigorous, capable of covering 6 m × 6 m within a few years
- Flowers May — among the earliest reliably mass-flowering climbers, a key spring seasonal marker
- Cultivar ‘Rubens’ (pink) and ‘Grandiflora’ (large white) are the standard garden forms
- Pruning Group 1 — flowers on previous year’s wood, prune lightly only after flowering
Pet caution: Mountain clematis is listed as potentially harmful to cats and/or dogs. Keep pets from grazing on it, and contact a vet if you suspect your animal has eaten some.
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Related plants
Cross-check Mountain clematis against your zones