The Rose of Sharon is a medium to large shrub or a small tree. The plant is in the hibiscus family and known scientifically as Hibiscus syriacus and commonly called either Rose of Sharon or Shrub-Althea. The Rose of Sharon will grow 8 to 10 feet tall, and it will have a spread of 4 to 10 feet. There are many different cultivars that are hardy in USDA planting zones 5b through 9a.
Choose a location that has full sun to part afternoon shade. Young plants will need shade from the hot afternoon sun in the southern growing zones. The area should drain well and not have standing water after a hard rain. Plant the Rose of Sharon in early spring, after all threats of frost are over.
Dig a hole three times the diameter container and the depth of the root ball. Remove any grass or weeds that may be in the soil; amend the clean soil with one part compost to two parts clean soil.
Remove the starter bush from the container and gently knock off some of the growing medium. If the starter was planted in a good quality potting mix, it does not have to be removed.
Place the bush in the planting hole; cover the roots halfway with amended soil. Run a gallon of water over the soil to compact it around the roots. Continue to fill the hole, until the soil is level with the surrounding ground.
Water the bush to completely saturate the soil immediately after planting. Keep the soil evenly moist throughout the growing season. Occasional water will benefit the root system throughout the fall and winter.
Apply a balanced time released fertilizer in the spring. Time release fertilizers come in various releases, such as 3-month, 8-month and 12-month. An 8-month release is best for this bush. Follow manufacturer's directions on the proper amount to use per age of the bush.
Spread a 3-inch layer of shredded bark mulch in a 3-foot diameter around the bush. Expand the diameter as the bushes spread becomes larger. This will ensure moisture retention, and it will keep the area free of weeds.
Prune the bush back in very early spring to create larger flowers. Prune in the winter if you'd like more flowers; if you want more flowers, they will be smaller. Cut off dead or damaged branches at any time.