Brugmansia is a small, tropical tree with large, trumpet-shaped flowers that droop gracefully from the branches. Often called "Angel Trumpets", these plants are beautiful but very poisonous. Brugmansia x arborea is a rare, white-flowering, high-altitude species of brugmansia native to the Andes in South America. This species has smaller flowers that nod rather than hang straight down. The care needs of "Arborea" are the same as other species of brugmansia.
Brugmansias are tropical plants. As such, they thrive in warm climates. B. arborea, however, is a high-altitude plant and is the only species of brugmansia that can tolerate light frosts, making it a good choice for home gardeners who live in more temperate regions. Brugmansia x arborea can be grown as a perennial outdoors in United States Department of Agriculture (USDA) growing zones 9 or warmer. In cooler growing zones, it is either grown as an annual or planted in a container and brought indoors before the first deep freeze of winter.
Brugmansias thrive in full sun, and B. arborea is no exception. Still, the intensely hot rays of afternoon sunlight can scorch the leaves of this plant in hot climates. Home gardeners who live in tropical or subtropical areas should place the plant in a location where it will receive morning sun and afternoon shade. Those in more temperate climates can plant B. arborea in full sunlight.
Water and Soil
Angel trumpets thrive in moist, cool soil. Brugmansia x arborea is more drought-tolerant than many other species of brugmansia, however, due to the adaptation of the plant to the dry, rocky, high-altitude slopes of the Andes mountains. Still, maintaining average levels of moistness in the soil is best for the plant. Water B. arborea when the top 1 to 2 inches of soil are dry, and place 2 inches of mulch around the base of the tree (but not touching the trunk) to help retain moisture in the soil. Watch for drooping leaves, as this is a sign that the tree needs watering.
B. arborea is a very fast growing tree. The plant benefits greatly from regular fertilizing. The more you fertilize the plant, the more flowers it will produce, according to horticulturists with the University of Wisconsin. Fertilize the tree with a water-soluble, balanced fertilizer made for tropical plants. Feed B. arborea often during the growing season--as much as twice a week--but much less often during the winter. Plants that go dormant should not be fertilized in the winter at all.
Prune container-planted B. arboreas in the spring after you move them back outside. Do not move the plant outside until all danger of frost is past. Prune to shape the plant to fit the container. Brugmansias planted outdoors should be cut back almost to soil level in the fall if you wish to encourage bushier spring growth.