Rose Mallow Plant Purplish red moist areas 393914 moist areas Plant while the tree is dormant Rose Mallow Varieties and Characteristics In order to properly care for your Rose Mallow‚ you will need to meet a number of growing requirements․ Rose Mallow thrives in full sun․ This flower requires at least six hours of sunlight per day to bloom․ The plants prefer moist‚ well drained soil as they are native to and grow beside lakes‚ ponds and marshes․ Compost or similar organic material may be added to improve the structure‚ moisture holding capacity and nutrient content of the soil․ Given that Rose Mallow can grow between three and seven feet (0․91 and 2․13 m) tall‚ the plant must be spaced out properly around the garden to prevent diseases and to encourage foliage and flowers on the plant․ With sufficient care‚ Rose Mallow plants can bloom from mid to late summer until early fall․