Angel's trumpet, a tropical shrub in the nightshade family, produces fragrant, trumpet-shaped flowers in shades of white to purple that reach up to 12 inches in length. The plant blooms in spring, summer and fall, and the tubular flowers emit a strong aroma during the evening hours. Native to tropical South America, angel's trumpet cannot tolerate cold temperatures. The plant survives winter outdoors in USDA hardiness zones 8 through 10. Elsewhere in the country, gardeners grow angel's trumpet as an annual or overwinter the plant indoors.
Plant angel's trumpet during mid-spring at a site that receives full, direct sunlight and consists of moist, well-drained soil. Cover the soil with compost prior to planting and use a tiller to cultivate the area, incorporating the compost into the soil to improve drainage and fertility. Space plants 3 to 4 feet apart.
Water the plant when the top inch of soil is dry to the touch, about once every four to five days. Soak the soil to a depth of about 6 inches to ensure the roots can absorb plenty of water. Do not allow standing water to accumulate to avoid root rot.
Feed angel's trumpet once per month during spring and summer to provide sufficient nutrition for rapid growth and flower development. Apply a 10-10-10 fertilizer according to the manufacturer's directions for the best results. Moisten the soil prior to feeding to reduce the risk of root burn.
Prune the plant once per year during late winter or early spring using hedge clippers. Cut back overgrown branches by several inches and remove any dead or damaged limbs to improve the plant's health and appearance.
Lift angel's trumpet in zones above 8 during fall, just before the first frost of the season. Plant in a container just large enough to hold the entire root system. Transfer the plant to a basement or garage and keep at a temperature of about 40 degrees F. Apply water once every two to three weeks. Replant outdoors the following spring, after the threat of frost has passed.