Trumpet vine can be either a gardener's dream or her worst nightmare. This aggressive vine grows rapidly, covering everything in its way, and rapidly reseeds itself. It can quickly take over a garden, and its flowers, also called "Cow Itch," can cause an itchy rash. On the plus side, it is an attractive plant, with bright orange and red trumpet-shaped flowers that lure hummingbirds and harmless bumble bees into the garden. The flowering vine can grow up to thirty or forty feet and does well on a trellis, fence, or will grow up a tree.
The trumpet vine is grown from seeds found in 3 to 6 inch pods that grow at the base of the flowers. These are filled with many flat seeds. The seeds are lightweight and designed to travel on the wind. If the seeds are allowed to disperse naturally, new vines will grow wherever they land and take root. To avoid this, pick the seed pods as they appear.
Trumpet vine seeds can be planted directly in the soil after frost is no longer a danger. Plant the seeds 1/4 inch deep in warm soil in a sunny location. Mix compost into the soil before planting. Add a general purpose fertilizer when planting as these fast-growing vines are heavy feeders. Continue to provide plenty of water, and fertilize every two to three weeks with the same general fertilizer. When the buds set, just before blooming, switch to a high-phosphorus fertilizer.
Without something to grow on, the trumpet vine will take the shape of a small bush. For this reason, plant your trumpet vine seed pods near a trellis or fence, or install something for the plant to climb.