Allamanda cathartica is a woody evergreen, tropical bush vine. It is often called by its common moniker, Golden Trumpet.
This vining plant boasts deep yellow trumpet flowers spanning 5 inches (12 cm).
Allamanda cathartica flower trumpets image by Forest and Kim Starr; CC.
It blooms consistently through the summer and into the first frost of fall in typical conditions; but can bloom all year in a tropical environment.
The foliage appears as bright green, leathery leaves that grow up to 4 - 6 inches long (10 to 15 cm).
Allamanda cathartica (Yellow allamanda) photograph by Forest and Kim Starr.
Allamanda cathartica can be trained to grow onto a trellis as a vine or pruned into a bush shape.
This woody climber can grow up to 10 - 20 feet tall (3 to 6 m) and 3 - 6 feet (0.9 to 1.8 m) wide. It is able to grow faster in warmer weather.
Grown best in hardiness zones 10 to 11, the Allamanda cathartica plant requires warm temperatures to grow and bloom properly.
It prefers full sunlight exposure but will tolerate partial shade.
Best grown in loamy or sandy soils, this plant requires a cooler temperature for its roots than its vines. It does well in fertilized, moist soils.
Golden Trumpet plant, photograph by Forest and Kim Starr; CC.
For optimum growth, the woody vine should be fertilized and watered regularly during its growing season.
Organic mulch is recommended for application around the base of the plant to keep the soil moist and at a lower temperature.
The vines only produce blooms on new growth, and pruning is recommended for the most cohesive look.
Allamanda cathartica may be cut back in early spring to ripe or half-ripe wood in order to stimulate more growth during the growing season.
Allamanda cathartica, image by Forest and Kim Starr; CC.
I hope that you enjoyed this guide on how to grow Allamanda cathartica. You may also enjoy the following Gardener's HQ growing guides: How to grow Catharanthus and Vinca minor plants.