Tough and beautiful, woody trumpet vines (Campsis radicans) rise to 13 feet (4 m.), scaling trellises or walls using their aerial roots. This North American native produces 3-inch (7.5 cm.) long, bright orange flowers in the shape of trumpets. Pruning trumpet vines is critical to establish a strong framework for the plant. Read on to learn how to prune a trumpet vine.
How to Prune a Trumpet Vine
It takes two or three years for a trumpet vine to develop a strong framework of branches. To accomplish this, you’ll want to start pruning trumpet vines the year after you plant them.
Since trumpet vine blooms in midsummer on current year’s growth, severe fall pruning won’t limit the vine’s flowers the next summer. In fact, pruning trumpet vines properly encourages the plants to produce more flowers every summer.
The plant is prolific and sends up multiple basal shoots. It’s a gardener’s job to reduce that number to begin building a long-term framework for the flowering shoots.
This process requires cutting trumpet vine plants back in the fall. The following spring, it’s time to select the best and the strongest vine shoots and prune back the rest. This pruning procedure is appropriate for newly planted trumpet vines and also for mature trumpet vines that need renovation.
When to Prune Trumpet Vines
Your first job is to harden your heart to cutting trumpet vine plants in autumn. When you are cutting trumpet vine plants back, you can prune them off at ground level or leave up to 8 inches (20 cm.) of vine.
This type of trumpet vine pruning encourages vigorous basal shoot development in spring. When new growth begins, you select several of the strongest shoots and train them to the supporting trellis. The rest must be cut to the ground.
Once a framework of several strong shoots extends over the trellis or allotted space – a process that may take several growing seasons – trumpet vine pruning becomes an annual affair. In spring, after all danger of frost is past, you prune off all lateral shoots to within three buds of the framework vines.