Double Lavender Angel's Trumpet - Datura. The Angel's Trumpets can be grown as tender shrubs in warm climates, annuals in the north or as patio plants, outside in the summer and indoors in the winter. They prefer full sun and are summer blooming, July through September. Double Lavender is a fragrant and charming Angel's Trumpet that produces a 4" double lavender trumpet bloom that exudes a sweet perfume. It grows 18-24" tall.