Clematis vines climb trellises or anything else that they can wind their tendrils around. There are three main types of clematis — early-flowering, large-flowering and late-flowering varieties. While all three bloom profusely, they flower at different times. Early- and late-flowering types bloom only once a year, in spring or fall, so they don’t require deadheading. Large-flowering clematis blooms in early summer but can provide a second period of blooms in fall if the vines are deadheaded. Removing the spent flowers halts seed production and encourages these vines to flower and set seed a second time.
The vines don’t require a deadheading after they bloom for the second time in fall; instead, cut the entire vine back to a 12- to 18-inch height.