What: The bold foliage and quick growth make Clematis armandii “Snowdrift” a very useful vine, but it really stands out in the garden when it is in full bloom from late winter to early spring. A profusion of small pure-white flowers cover the vine like a sudden snow flurry. Each flower is part of a larger cluster and has a sweet fragrance that perfumes the air. The leaves are fully evergreen and have a pleasant bronzy tone when they first emerge. The bronzy new growth looks great against the white flowers.
Where: This evergreen clematis is a large grower and requires plenty of space to spread. It will grow best in light to open shade or full sun, if the location is not a hot spot. Provide a site with rich, well-drained soil where it can be occasionally watered during dry weather.
Size: “Snowdrift” will grow to be 40 feet tall with a spread of 30 feet when mature.
Care: Plant “Snowdrift” vines that are well rooted and at least two years old. In our climate, planting too deeply can smother the roots. Set young plants at the same depth they were in their nursery pots. Clematis are heavy feeders and appreciate fertilizing in spring. This clematis blooms on one-year-old stems, so prune lightly in late winter, only removing congested or tangled growth, or if heavy pruning is required do it immediately after flowering in spring.
— Richie Steffen, Great Plant Picks