The gardenia is a genus of more than 200 species. These low-growing shrubs develop rich green foliage and fragrant white flowers. Gardenia variations grow up to 8 feet tall and require generous attention for optimal growth. These temperamental shrubs react adversely to temperature and location changes and are not cold-tolerant. Gardenias do best in temperatures between 68 and 74 degrees Fahrenheit, with low temperatures never exceeding 60 degrees. The planting location can determine whether the gardenia thrives.
Place the gardenias in a slightly acidic area with pH ranges between 5.0 and 6.0. Make sure the location is well-drained and provides at least six to eight hours of full sunlight each day.
Dig a hole equivalent to the depth and width of the root system. Plant multiple bushes 3 to 6 inches apart to accommodate growth.
Fill the hole halfway with soil. Irrigate the hole to remove air pockets, lay the remaining soil and irrigate again. Make sure that the gardenia's final planting surface is slightly elevated from the surrounding surface.
Irrigate the gardenia bush regularly to provide it with 1 to 2 inches of water each week. Use a slow irrigation process. Irrigate with smaller, more frequent irrigation levels in sandy soils.
Apply a layer of mulch, approximately 3 inches thick, around the diameter of the bush to preserve moisture.
Prune the gardenias after flowering. Trim away dead wood, pinch back blooms to promote heavy branching and prune out straggling branches and spent flowers. Use sharp, sterile shears to prune the bush.
Feed the gardenia bush with fertilizers designed for acid-loving plants. Select gardenia blends when available. Fertilize monthly for continuous blooms; otherwise, fertilize at least two to three times a year, beginning in early spring. Always feed the gardenia after pruning.
Remove any weeds or surrounding vegetation to prevent competition.
Inspect the gardenia often to confirm its overall health. Look for signs of disease such as stunting, wilting, black or white mold on foliage, leaf spots and yellowing. Treat fungal diseases and insect infestations immediately to prevent permanent injury to the bush.