Gardenias grow extremely well in the warmth and humidity of the South. An evergreen shrub, it will grow to a height of 3 to 5 feet, depending upon cultivar. The flowers vary by cultivar as well, blooming in both single and double blooms. One aspect of the gardenia is constant, however, and that is the scent. Because of their fragrance, most Southern gardeners choose to grow the gardenia as close to the house or patio as possible. Grown in pots or in the garden bed, varieties for Southern gardens include August beauty, golden magic and mystery. The gardenia is hardy in USDA zones 8b to 11.
Wait until fall or spring to plant the gardenia.
Choose an area of your garden that receives shade and no competition from the roots of large trees.
Amend the soil in the planting area. Dig up the area to a depth of 10 inches. Turn the soil and smash any large clumps of dirt and remove any rocks or other debris. Add a 3-inch layer of compost and a 1-inch layer of sphagnum peat moss and mix these in well, using the gardening fork.
Dig a hole the same depth and twice the width as the pot in which the gardenia is growing. Carefully tip the gardenia out of the pot and lower into the hole. Try to disturb the root system as little as possible.
Fill the hole halfway with soil, then fill the hole with water. Allow the water to drain and then finish filling the hole with soil, tamping gently around the base of the plant.
Build a water basin around the gardenia by forming the soil into a circular dam. Mound the soil 3 inches high and 6 to 8 inches wide and form it around the base of the plant, 8 to 10 inches away.
Water the soil around the gardenia until it is very wet. Always water the soil, not the plant, because water on the leaves will cause stains. The Southern gardenia will need water twice a week during its first two months in the ground. Fill the watering basin completely when watering.
Apply a 3-inch layer of mulch, such as shredded bark, around the base of the gardenia, keeping it at least 3 inches from the base of the plant. This will help the soil to remain moist and cool in the hot Southern summer.
Fertilize your gardenia in mid-March and late June. Extension agents at Clemson University suggest using fish emulsion or blood meal. Any acid-type fertilizer will work.
Protect your gardenia from frost by covering it with a sheet or tarp.
Prune the gardenia in the late summer by removing dead flowers and branches.