Gardenias are flowering evergreen shrubs native to tropical and subtropical regions of Africa, Asia and Australia. Gardenias can grow up to 49 feet in height, though most only reach about 6 feet. Gardenia plants are most commonly planted as solitary specimens, although they also make ideal border plantings. Gardenias are prized for the fragrant white flowers they produce during late spring and early summer. They require only basic care to grow and flower in temperate regions of the United States.
Plant gardenias during early summer in a location that receives six to eight hours of direct sunlight each day. Spread a 1-inch layer of organic compost over the planting site and use a garden hoe to incorporate it into the soil. Space gardenias at least 4 feet apart.
Spread a 4-inch layer of mulch over the soil surrounding gardenia plants to insulate the soil, improve moisture retention and suppress weeds. Replenish the mulch as often as necessary to keep the layer around 4 inches deep.
Water gardenias once every two weeks during spring, summer and fall with deep, thorough soakings. Reduce the frequency of watering to once every three weeks during winter, when the plant is not actively growing.
Feed gardenias once per month during spring and summer using cottonseed meal. Apply following the directions located on the package. Do not fertilize during the fall and winter months, when the plant is dormant.
Prune gardenias once per year in late winter, just before new growth begins in spring. Use pruning shears to remove inner limbs that have grown excessively long to increase air circulation and encourage the plant to grow in a compact habit.