Alice Fisk has the largest flowers for cold-hardy clematis. Its blue flowers are 6 to 9 inches wide. It flowers in May, June and September and grows to a height of 6 to 8 feet. It is hardy from climate zone 3 to climate zone 9 of the USDA climate zones.
Allanah clematis vine has very large 5 to 7-inch wide flowers that are dark red. This clematis flowers from June to September and grows very quickly. It can reach 6 to 8 feet when fully grown. It is hardy from climate zone 3 to climate zone 9 of the USDA climate zones.
Alpina Constance has pink flowers about 1 to 2 inches wide. This clematis is a spring bloomer, flowering from April to May, and growing 6 to 8 feet. The vine is hardy from USDA climate zone 3 to climate zone 9.
Alpina Frances Rivis has blue, bell-shaped flowers around 1 to 2 inches wide. It flowers from April to May and can reach 6 to 8 feet. It will grow from climate zone 3 to climate zone 9.
Alpina Helsingborg has deep purple, bell-shaped flowers around 1 to 2 inches wide. It flowers from April to May and grows to 6 to 8 feet. It is hardy from USDA climate zones 3 to 9.
Alpina Pamela Jackson has blue bell-shaped flowers around 1 to 2 inches wide from April to May. It can reach a height of 6 to 8 feet. It, too, is hardy from climate zone 3 to climate zone 9.
The clematis vine Alpina Pink Flamingo has pale pink-colored flowers around 1.5 inches wide. It flowers from April to May and can be especially tall, sometimes reaching 10 feet when mature. It is hardy from climate zone 3 to climate zone 9 of the USDA climate zones.
Alpina Ruby has mauve-colored bell-shaped flowers around 1 to 2 inches wide. It flowers from April to May and can grow as tall as 6 to 8 feet. The vine is hardy in climate zones 3 to 9.