Seeds from Clematis florida viennetta. The Clematis Vienetta, is a knockout clematis that embelishes stunning white flowers with large pom-pom centers frosted in blackberry purple. It is a good container plant for the conservatory or sunroom and flowers till early winter. Long flowering season & long individual flower life with inner ‘ruff’ of sepals opening slowly over 10-14 days. Can be planted outside. Fully winter hardy to -10 degrees C. It is hardy in zones 4-9.