Trumpet vine (Campsis radicans) is spectacular and requires two or three years to establish itself and start blooming. Prune weaker branches from young vines to leave one main stem and branches. When the vine matures, cut the flowering shoots that have grown away from the supported branches back to the main branches in early or late winter. These branches will regrow the next year. Trumpet vine flowers on new growth, so pruning in spring does not affect flowering.
Cut back an old branch or two every year to maintain control. A trumpet vine grown too large and ungainly may be cut to within 12 inches of the ground in late winter to renovate it. Begin training the strongest new shoots to the trellis in spring.
Chinese trumpet vine (Campsis grandifora) is a native of East Asia, China and Japan.
Campsis, or trumpet vine is a self clinging climber grown for its clusters of showy, exotic orange to red or yellow, trumpet shaped flowers.