Tender shrubs and small trees native to South America, the five species of brugmansia, also known as angel's trumpets, produce large, fragrant, trumpet-shaped flowers in spring through fall. In frost-free areas, blooming continues nearly year-round when the plants receive proper care. While growing brugmansia in the ground yields the best results, the plants require overwintering indoors in areas cooler than USDA hardiness zone 10. Gardeners in areas where winter frost is a danger typically grow brugmansia plants in large containers or tubs for easier transport indoors during the winter.
Plant brugmansia during the spring in a location that receives full sunlight throughout the day and has well-drained, rich, fertile soil. Dig a hole in the soil of equal depth and twice as wide as the plant's root ball. Insert the roots into the hole and cover with soil. Water lightly to collapse any air pockets. Plant in a 10-gallon pot in areas cooler than USDA hardiness zone 10.
Water once every five to seven days to keep the soil consistently moist. Decrease the watering frequency to once every 10 days during winter, when the plant is dormant and requires less moisture. Pour water directly over the soil to prevent wetting the foliage, which can contribute to fungal disease.
Feed brugmansia plants during spring, summer and fall once every four to six weeks, using a 19-5-9 NPK fertilizer. Water the soil lightly before applying to avoid burning the plant's roots. Follow the dosage directions on the package for best results.
Prune the plants once per year during late winter, just before active growth resumes. Use hedge clippers to cut back any excessively long limbs to improve the plant's aesthetic appeal. Remove any damaged or diseased growth to increase the overall health of the plant.
Transfer brugmansia plants indoors during fall in USDA hardiness zones 9 and below once the temperature drops below 40 degrees Fahrenheit. Keep in bright light and water once every 7 to 10 days. Move the plant back outdoors the following spring, just after the final frost of winter.