Two notable exceptions are the species C. heracleifolia and C. integrifolia which are herbaceous, and fit well in a perennial garden border. There are several hundred species of clematis world wide. Clematis enable the gardener to have masses of bloom from late winter to late fall. To accomplish this, varieties with different bloom times can be grown together or planted in complimentary areas of the garden. Clematis can be chosen to enrich any garden, no matter how large or small.
Most clematis varieties produce single flowers.
Some varieties produce double flowers, others produce both single and double flowers. Most double flowering varieties will bloom double on the previous season's growth, early in spring. They will than bloom single on the current season's growth in late summer or early fall. If pruned improperly, these varieties will produce single blooms only. The blooms of the clematis often change color, some very markedly through the life of each flower, particularly when grown in the full sun.