This hibiscus plant is a rounded, sturdy, vigorous, woody-based, hairy-stemmed, somewhat shrubby perennial in the Mallow family. It grows about 3â â 7â feet long and 2â â 4â feet wide.The Swamp Mallow produces large flowers, which grow 10â â 12â inches wide. The bloom color varies, but the flowers are mostly pink with dark pinkish centers. The bloom time of this plant is from August to September.