With its long red, yellow, and orange flowers, the trumpet vine can be a beautiful addition to your yard. These relentless growers attract hummingbirds and can be a birdwatcher's delight, but they spread so aggressively and are so pest-resistant that you must be vigilant in holding them to their proper place. The trumpet vine truly has plenty of benefits, but it's important to know what you're getting into, and how to keep it from overtaking your garden.
The most recognizable feature of this plant is its elongated, trumpet-like flowers from which the name is derived. Adding to its exotic beauty, the trumpet vine's bell-shaped blooms come in red, yellow, or orange, but the latter is most common. The petals have a waxy feel, and their dark, shiny leaves grow up to 15 inches.
Not only are the vibrant colors of the trumpet vine's flowers alluring to hummingbirds, but the steep curves of the petals easily accommodate their long tongues and hold the nectar they love so much. The trumpet vine is so hummer-friendly that it has earned the nickname hummingbird vine, and when planted next to a shrub for breeding, you'll be sure to have quite a show all season long.
As pleasant as the trumpet vine's flowers are to humans and hummers, the vine can become quite unruly, to the point of being destructive. This is a highly invasive species, and its runners can spread faster than some gardeners can trim them back. Trumpet vine is known for covering entire structures, and can even strangle trees and damage foundations with its spreading root system. The rapid growth can be an asset to those seeking to cover a trellis or arbor, but it is best to keep this plant away from any structure you don't want overtaken.
Because of its rapid spreading, it is important to give trumpet vine a structure that can withstand its growth. It will find something to cling to, and when left unchecked, trumpet vine has found its way onto roofs, damaging shingles. It's best to keep this plant away from your home, trees, and other plants you don't want choked out, and give it a sturdy structure that can hold its weight. The upside of such quick growth: its dense foliage and orange blossoms make for a beautiful rustic overhang for which you don't have to wait multiple seasons.
One of the reasons trumpet vines spread so aggressively is their hardiness. They can thrive without regular watering, as the amount they get from natural rainfall is enough to keep them going. Fertilizer is not only unnecessary but can actually damage the plant, as excess nitrogen hinders growth. No special nutrients are needed for trumpet vine's growth, either.
Trumpet vines prove their resiliency by thriving across a range of temperatures. This hard-to-kill runner prefers the hot, humid climates of the southeast and does well in USDA zones 4 to 9, blooming in late summer and autumn. It spreads less in hotter environments, and does best in full sun to partial shade. A slightly acidic soil pH of 6.5 to 6.8 is ideal.
The trumpet vine is fairly resistant to pests and diseases. Normally this is considered a good thing, but some growers wish this plant had some sort of predator to keep it in check. This is partially why it grows so rampantly: its only check is you, the gardener.
The lack of diseases or pests means the best tool at your disposal to keep this plant from going too far is a sharp set of shears. Prune your trumpet vine to nearly ground level, letting just a few buds remain. The flowers bloom on only new growth, so do your pruning early if you want to see their beautiful blossoms.
Because of its hardiness, gardeners who want to rid themselves of their trumpet vine must resort to extreme measures. The most effective but difficult way is to dig it out by the roots, but repeatedly scalding it with hot water also works, as does a solution of diluted vinegar sprayed across the plant. Applying rock salt to the ground underneath will also do the trick, but this can harm the soil and surrounding vegetation.
Though not that dangerous, trumpet vine does release an irritant that causes a mild to severe skin rash — an effect that lends it the less pleasant nickname "cow itch vine." If you want to avoid this, be sure to wash your hands thoroughly after handling any part of the plant. You can also wear gardening gloves and long sleeves when working with the vine.