Clematis are beautiful and hardy perennial plants, most of which are climbers. Each species has its own unique look, with differing bloom times that can range anywhere between May to October, with single or double flowers. Clematis flowers make excellent cut flowers for a vase. Simply cut them from the vine as soon as they are open, and they can last four or more days.
Clematis alpina is easy to grow and surprisingly very hardy, given its delicate look. The flowers range from 1 to 2 inches in diameter and bloom from spring to early summer, and often bloom again in the fall. It is known for its bell-shaped blue flowers and white centers. The seed heads remain throughout the winter. Clematis alpina begins flowering from the previous year's growth, so remove any dead growth in the spring after new foliage has surfaced.
Clematis integrifolia works well as a groundcover, as it is not a climber and does not wrap its vines. It grows in a mound up to 18 inches high. The flowers are bell-shaped and thick, and are usually about 1 inch in diameter and come in a range of blues with white stamens that bloom from May to July. The leaves can grow up to 6 inches long. It should be cut back to the ground in late fall or early spring before it begins new growth.
Clematis macropetala is fast grower and very winter hardy, with 2- to 3-inch flowers in the burgundy to purple range that bloom in the early spring and often again in late summer. They are climbers and great for trellises. They prefer a shady site, but can do well in direct sun. Clematis macropetala blooms on the previous year's growth. Prune only to maintain shape and remove death growth, but only after new foliage has surfaced.
Clematis tangutica is native to China, and is easily recognized for its bell-shaped, bright yellow flowers with deep green foliage. They bloom from July to October and can reach up to 15 feet. They work well in poor soil and are great to use as ground cover. They should be cut to the ground each winter.
Clematis viticella produces small flowers that bloom for three months, from July to September. They are resistant to the fungal problems that affect other species of clematis. They prefer the sun. Flower shapes can be anywhere from open bells to unattractive and twisted forms. Colors include purple, red and burgundy. They can reach up to 12 feet tall and should be pruned severely in early spring.