The Rose of Sharon is a small, easy-to-grow tree that tolerates any type of soil. It can be planted outside or in containers, and grows well in Zones 5B through 9A. The Rose of Sharon is a slow grower that produces large, summer flowers. The blooms might be lavender, blue, pink, purple, red or white. If planted in the ground, it can grow to a height of 10 feet and up to 10 feet in width.
Dig a planting hole twice the size of the root ball and as deep as the root ball. If you want to leave the Rose of Sharon in a pot, be sure to use a pot that is twice the width of the root ball. Center the plant in the planting hole and backfill with soil. Gently tamp the soil down as you are backfilling. For pots, line the bottom of the pot with small stone, then add at least 6 inches of soil. Set the plant in the pot. If the top of the root ball is within 3 inches of the top of the pot, backfill with soil. If not, remove the plant, then add more soil to the bottom of the pot.
Create a watering ring around the perimeter of the planting hole. The watering ring should remain in place during the first growing season, and can be leveled out at the beginning of the next growing season. The watering ring helps divert water to the outside roots. It also helps to conserve water when watering.
Mulch the Rose of Sharon with 3 inches of compost or pulverized bark. The mulch helps keep moisture in the ground and promotes a healthy plant.
Water the Rose of Sharon initially with 1 inch of water. Watering deeply promotes deep root growth and a healthy plant. If you do not give enough water at each watering (shallow watering), the plant will develop a shallow root system, which promotes an unhealthy plant. Unhealthy plants attract viruses, pests and fungi.
Water the Rose of Sharon every subsequent week, with 1 inch of water. Prune the plant as needed for dead and decaying wood and plant matter, especially in the spring. Stop pruning 6 weeks prior to the first frost to give the plant time to "harden" before winter.