Rose of Sharon is actually a variety of hibiscus, which is native to Indian subcontinent and other Asian countries. Planting rose of sharon is possible in variety of zones as it is adaptable to multiple climates.
Blue Bird Rose of Sharon An incredibly beautiful shrub with an extraordinarily long flowering time! Saucer-shaped blooms with overlapping petals of azure-blue, accented by red-purple throats, are produced nonstop from midsummer to frost, opening 3-5" wide. Will form an open fan-shaped bush 6-8' tall and easily used for a screen or hedge. Ships in 4" pots. Zones 5-8 Hibiscus syriacus ‘Blue Bird’
How to Prune a Rose of Sharon Bush to Create a Rose of Sharon Tree
Rose of Sharon, with its profuse blooms and resistance to pests, is one of the easiest shrubs to grow. It can also stand extreme pruning, if you wish to turn yours into a small tree instead. Such "limbing up" -- removal of excess stems and lower branches -- can allow you to grow other plants or grass under its canopy. Heavy pruning will also reduce the number of flowers, though the remaining ones should be larger.