By Mary H. Dyer, Master Naturalist and Master Gardener Often known as mini angel trumpet or violet tubeflower, Iochroma is a dazzling plant that produces clusters of intensely purple, tube-shaped blooms throughout summer and early autumn. This fast-growing plant is actually a member of the tomato family and is a distant cousin of brugmansia, another absolute stunner. If you’re looking for a sure-fire hummingbirdmagnet, you can’t go wrong with Iochroma. Want to learn how to grow Iochroma plants? Read on! Iochroma Growing Conditions Iochroma (Iochroma spp.) is suitable for growing in the warm climates of USDA plant hardiness zones 8 through 10. However, most varieties can be grown successfully in climates as far north as zone 7, but only if the roots are well insulated with a layer of mulch. If temperatures drop below 35 F. (2 F.), the plant may die to the ground, but will resprout in spring.