Ruellia multisetosa (Columbian Petunia) is a native to Bolivia, a large shrub that can get up to 5-10 ft tall and is grown in USDA Zone 9-11. It produces beautiful pink flowers from spring through summer. The leaves on this plant are large, hairy and dark green. This plant prefers part sun or shade and regular water. In full sun, the leaves may become pale and the plant may dehydrate. As it is a fragile plant, support may be required to keep the stems upright. It can tolerate temperatures as low as 30F and will freeze to the ground in cold regions, though it will return quickly when temperatures rise. This fast-growing plant also takes well to cuttings and will root easily.
To grow Ruellia multisetosa in cold regions, it is best to keep it in a pot. Choose a pot with good drainage and plant the Columbian Petunia in a well-drained soil with plenty of organic matter. Place the pot in a sheltered area and choose the location wisely, avoiding draughts and strong winds. Water regularly, around once or twice a week, and fertilize during summer to help the plant grow.