Flowering is from spring to summer, with variations according to the site. In Melbourne, the yellow flowering form is flowering heavily at Christmas, whereas it flowers well in Cairns in June. On mountain ranges inland from Port Macquarie, the hillside is an incredible mass of white blooms in February. In Brisbane, the white-flowering form in remnant vegetation may commence in June but usually there are few flowers on plants in the western suburbs before August with flowering mostly continuing until about Christmas time. The flowers are large, 10-19cm, white, yellow or sometimes pink, with dark red centres.
Leaves are dark-green, simple, or lobed and large and stems are rough, or prickly.
The species name refers to the different shaped leaves found in this species. Hibiscus heterophyllus occurs in shady and swampy eucalypt forests, gullies and rainforest edges on soils ranging from loam to granitic or poor and gravelly. Not only will blooms which produce nectar feed nectar-eating birds and predators but they will also attract insects for insect eaters, provided there are protected water sources and nesting places for birds. In addition, the seed capsules can provide for seed-eaters. Thus, apart from any aesthetic appeal of birds and insects, plants such as Hibiscus heterophyllus which attracts birds and predators encourage natural pest control as the insects use the plant as a food source and are themselves controlled by a wide range of predators.