Color: Blue Flower Size: 4-6″ (10-15cm) Flowering Period: June-Sept Mature Height: 9-12′ (3-4m) Pruning Group: C Planting Aspect: Sun/ Partial Shade USDA Zone: 3 Suitable For Container: Yes Foliage: Deciduous Price Group: Standard About Perle d’Azur The 4-6″ (10-15cm) flowers open light violet fading to sky-blue. The long bloom time combined with abundant flowers make this a favourite to many clematis enthusiasts. Mature height 9-12′ (3-4m). Pruning group C.