Hibiscus 'Red Heart' is a winner of the Royal Horticultural Society Award of Garden Merit, and now it's available in tree form. Grafted onto a 3-foot-stem, this tree grows to a mature height of 7 feet tall with a 6-foot-wide spread. 'Red Heart' has an upright, bushy habit of lobed dark green leaves and a long flowering season. Borne singly, the funnel-shaped bicolor flowers are simply dazzling with pristine white petals and a dramatic deep red eye.