Plant in full sun to light shade and water regularly spring through summer. Hardy to 10 to 15° F. Plant on a fence or trellis where stems can grow 12-15 feet with support or use as a groundcover. If used to trail over and down a slope, it can look like an avalanche of white flowers.

Clematis x cartmanii 'Avalanche' is a selected seedling from a cross made at Blackthorn Nursery, England by renowned plantsman Robin White. The pollen parent was Clematis paniculata and the seed parent was Clematis marmoraria - both evergreen species from New Zealand. The name Clematis x cartmanii honors the respected botanist Joe Cartman who first produced a cross between these two species.

We first started trials of this plant in 1999 for PlantHaven and we were licensed to produce and sell it in 2001. The original registered name for this plant when a patent application was filed was Clematis x cartmanii 'Blaaval' with "Avalanche" intended to be its trademarked marketing name, but unfortunately changes in patent laws related to when this plant was first sold overseas made it ineligible for a US Plant Patent and this patent application was abandoned. All royalties paid on sales of this plant, which we grew right up to when we closed the nursery in 2025 were made voluntarily by us. 

The information displayed on this page about Clematis x cartmanii Avalanche ['Blaaval'] is based on our research conducted about this plant from books in our nursery library as well as from information that is provided by reliable online resources. We also have included our own observations made about it as it grew in the nursery gardens and other gardens visited, as well how the crops of this plant performed in the containers when we had them in our nursery field. We also include comments received from others and welcome hearing from anyone who has information about this plant, particularly if it includes cultural information aiding others to better grow it.