- Name: Sweet Autumn Clematis - Other Common Names: Puawhananga - Scientific Name: Clematis Paniculata - Color: White - Plant Seeds: Outdoors After Frost / Fall / Cold Stratify / Indoors Weeks Before Last Frost - Plant Height: 20 - 30' - Plant Spacing: 4' - Bloom Time: Late Summer – Frost - Hardiness Zone: (3) 4 – 8 - Light Requirements: Sun - Part Shade - Soil & Water Preferences: Average - Quantity: 20 Seeds