Trozelia syn. Iochroma purpurea
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.
Although Iochroma prefers full sunlight, the plant benefits from shade in warmer climates where temperatures regularly top 85 to 90 F. (29 to 32 C.). Iochroma prefers well-drained, acidic soil with a soil pH of around 5.5. Water Iochroma regularly, and always water at first sign of wilt, as the plant doesn’t recover well from a severe wilt. However, don’t overwater and never allow the plant to become waterlogged. Be sure container-grown Iochroma is planted in well-drained soil, and that the pot has at least one drainage hole.Fertilize Iochroma monthly during the growing season using a balanced fertilizer with an NPK ratio below 15-15-15. Plants in containers benefit from regular application of a water-soluble fertilizer applied according to label directions. Prune Iochroma after blooming. Otherwise, prune lightly as needed to keep growth in check.