Gardenias are evergreen shrubs that grow 2 to 15 feet tall, forming glossy mounds of green foliage. During the blooming season, pale yellow or creamy white flowers dot the bush. These bushes grow best in USDA zones 8 to 11, where the temperature does not drop below 20 degrees F. This plant is particularly susceptible to bud drop, and requires more care and attention than other plants. Knowledge of how to create the right environment for the gardenia will keep it healthy and flowering.
Choose an area to plant your gardenia with full sun or light shade and moist, well-drained soil with a pH between 5.0 and 6.5. Mix organic compost into the soil to increase fertility. Try to locate your gardenia away from other plants, especially other shrubs and trees.
Dig a hole in the prepared area that is twice the width of the gardenia root ball and about the same height. Place the plant in the hole and backfill the soil around the roots. Tamp the soil down around the base of the plant to secure the gardenia.
Place a 2- to 3-inch layer of mulch around the plant. Gardenias do not like any competition for water and nutrients. Mulch will keep down the weeds around the plant and, at the same time, provide extra moisture for the plant.
Water the gardenia deeply after planting to settle the soil. Continue watering twice a week for the first six weeks after planting. When the buds come out on the shrub, keep it consistently moist--but not soaked. Large moisture fluctuations will cause bud drop.
Fertilize early in the spring, once the plant starts growing, with a slow-release, acid-producing fertilizer. Apply the fertilizer again in the height of summer. Follow the directions on the package for application instructions. Do not fertilize these bushes in the fall. This will encourage new growth that may die off with freezing temperatures.
Prune the gardenia with pruning shears right after it finishes flowering. Cut out straggly, dead and diseased branches. Also cut out old wood to promote new branching. Flower buds will develop on new growth, so do not be afraid to shape the plant.