Discover 10 of the best summer-flowering (group two and group three) clematis to grow. They bloom profusely over a long season, from early summer … Among the easiest Clematis to grow, Herbaceous Clematis are long-lived. Long Blooming Clematis Collection. Some for 6 weeks, others the entire summer. 10 pretty summer clematis to grow. Includes purple Jackmanii, re-blooming Crystal Fountain and fragrant, Sweet Autumn clematis. We grow all our Clematis in 1 litre, 4.5" pots, shipping from late May through the summer. News-Times, The (Danbury, CT) Published 1:00 am EST, Sunday, February 22, 2004 The varieties below just bloom a long time. Each variety was selected for its bloom time and striking flowers. Climbing clematis are wonderfully showy plants that produce huge blooms over a long … FREE … LONG-BLOOMING VARIETIES Some Clematis bloom in flushes with a heavy flowering in the early summer and a repeat performance in the late summer. They die to the ground at the end of each year, and have no twining petioles to help them climb. The All Summer Clematis Collection really showcases the spectacular features clematis have to offer. The collection includes General … Clematis the climber blooms all summer long. These perennial vines will provide flowers from early summer to fall.