Clematis 'Denny's Double' is an outstanding variety with beautiful, large, double mauve flowers in May, June and again in September which eventually turn a shade of light blue. It will occasionally produce purple/green petals.
This non-evergreen climber can be grown against a trellis, garden fence, wall, arches, pillars, pergolas, clambering over tree stumps and through large shrubs or planted in a container trained up bamboo canes or an obelisk.
When Mr and Mrs Denny of Broughton near Preston raised seedlings from Duchess of Edinburgh, among the progeny was this amazing result.