Gardenias, perennial shrubs native to China, Taiwan and Japan, produce fragrant white blooms in late spring and summer. Also known as cape jasmine, gardenias thrive in warm climates, where they often serve as border shrubs or specimen plants in out-of-the way places. Gardeners value the plants for their attractive, aromatic blossoms and ornamental, evergreen foliage. Hardy in USDA Plant Hardiness Zones 8 through 11, gardenias require only minimal care to thrive in the southern parts of the country. In colder zones, grow them in containers and overwinter the plants indoors to prevent cold damage.
Plant gardenias during spring or fall in a location that receives full sunlight to light shade and consists of rich, well-drained soil. Spread a 1- to 2-inch layer of crushed pumice stone over the site and incorporate it into the soil with a garden tiller to increase drainage. Space gardenias 3 to 6 feet apart.
Spread a 2- to 4-inch layer of organic mulch over the soil surrounding gardenias to improve moisture retention, provide insulation and reduce weeds. Leave about 3 inches between the plant's base and the mulch to allow air circulation.
Water gardenias once every five to seven days, or whenever the top inch of soil feels dry to the touch. Soak the soil to a depth of 1 to 2 inches to provide plenty of moisture for growth. Do not allow standing water to accumulate, or the roots may rot.
Feed plants once per month during spring and summer using an acidifying fertilizer. Water lightly before and after feeding to prevent root burn. Apply according to the directions on the label for the best results.
Prune gardenias during early spring before they resume active growth. Remove any dead or diseased branches and cut back any excessively long growth to keep the plant attractive and healthy. Remove blossoms as soon as they fade to encourage reblooming.