Hardy Hibiscus plants, also called Rose of Sharon, are low-maintenance perennials that produce spectacular, tropical-looking flowers and attractive foliage. These showy perennials return year after year and are available in an array of flower colors. Hardy Hibiscus usually bloom in mid to late summer and attract butterflies. Many varieties of these deer-resistant perennials perform well in moist areas and can be planted along sunny edges of streams, ponds and other water features. Gardeners also grow them in groups as flowering hedges. When buying hibiscus plants for sale online, make sure they are suitable for your grow zone. Other factors to consider are their mature height and spread, light requirements and flower color.