Rose of Sharon Hibiscus syriacus     Hardiness:  Zone 5 - 8 The Rose of Sharon can grow 8 - 12' high and 6 - 10' wide.  It is very erect,  but occasionally spreading, with numerous upright branches.  Leaves are medium to dark green in summer, changing to yellow in fall.  Flowers are five petaled, white to red or purple or violet, or combinations, single and double.