Haku Ookan This clematis is a showstopper. The rich violet pointed petals are offset by the striking large white stamens that bloom as a double flower in the spring and then a single flower in the fall. Mature height 6-9′ (2-3m). Pruning group B1 Vines are shipped and sold as well-rooted starter plants Flower Color Purple FlowerSize 5-7″ (12-18cm) Flowering Period May, June and September Mature Height 6-9′ (2-3m) Planting Aspect Sun / Partial Shade Foliage Deciduous Suitable asContainers Yes USDA Zone 4