Trumpet vines can grow in a number of soils and survive without being protected. Depending on the type of trumpet vine you want to grow, some thrive in cooler climates, like South Dakota, while others are tropical. For these tender perennials, you will need to grow them in a pot and keep them indoors during the cold weather. The flowers of the trumpet vines are like their name, shaped like a trumpet and they draw humming birds to feed on the nectar. Although there isn’t much of a scent with these flowers, they come in a variety of colors from yellow, pink, sky blue and dark red.
Find a Container
If you want to plant the tropical variety of trumpet vines, then you need to find a 3 to 5 gallon container. Make sure there are drainage holes at the bottom, otherwise the roots could rot. Cover the drainage holes with some shard, a piece of screen, or a coffee filter will work. These will allow the water to drain out, but not your soil.
Fill the container a third full of well drained potting soil. You can buy potting soil at the garden supply centers or make your own by mixing equal amounts of soil, compost perlite and peat moss.
Pop out the trumpet vine from the container it is growing in. Once the trumpet vine is out, examine the root section. If the roots are visible and growing around the outside of the rootball, gently tease them away. It is important to loosen them because if the roots are left growing around the rootball, they will eventually choke the plant to death.
Potting the Trumpet Vine
Place the trumpet vine into the container and make sure that the top of the rootball is a half inch below the rim of the container. If it is lower than that, add some more soil to the pot, or if it is higher than that, remove some of the soil. Once you have the soil right, center the trumpet vine in the pot. Add soil around the rootball but do not bury the rootball any deeper than where it was growing in its container. Firm the soil around the rootball with your hands.
Trumpet vines like to grow in sunny locations, but can grow in part shade. The thing to remember is, if you want a lot of flowers, then the sunnier the location, the more flowersthe trumpet vine will give you. Place the pot in a sunny location, before you water, otherwise the pot can be too heavy to move.
Water the Trumpet Vine
Give your trumpet vine a good drink of water. Keep the soil moist, but not soggy. Trumpet vines require a lot of water as they begin growing and as they are flowering. When the trumpet vine is done blooming, cut back on the watering. Allow the soil to dry out between watering because now it’s the time that the trumpet vine is preparing for dormancy. Trumpet vines do not use much water during the winter.
You can give the trumpet vine a shot of 5-10-5 liquid fertilizer. Only use half the recommended strength on the label and fertilize once every 2 to 3 weeks through the growing season starting in April. But when August arrives, fertilize the plant once. The trumpet vine needs only one last shot of fertilizer at the end of September. Apply no more fertilizer until April.
If you want to prune the trumpet vine to keep it a more manageable size, do so in the spring. Don’t prune it severely back.Sources:
Backyard Gardener: Allamanda cathartica (Compact Allamanda)
“American Horticultural Society A to Z Encyclopedia of Garden Plants”; Christopher Brickell; 2004