Description
Most gardenias are fairly adaptable shrubs tolerant of sun or semi-shade, and do best in a well-drained, humus-rich, acidic soil. Fall or spring is the best time for planting in warmer climates. Place in light to moderate shade, preferably with minimum competition from tree roots. Gardenias resent root disturbance. Use fertilizer for acid loving plants, and use iron compounds. Add plenty of organic matter, such as compost or ground bark to as large an area as possible. Mulch plants instead of cultivating. A good time to feed gardenias in these warm areas is mid-March, using an acid plant food, fish emulsion or blood meal. Fertilize the shrubs again in late June to encourage extra flowers on ever-bloomers or faster growth of young shrubs. Do not fertilize gardenias in the fall. Doing so will stimulate tender growth. Prune shrubs after they have finished flowering to remove straggly branches and faded flowers. Water gardenias regularly. Drip irrigating the shrubs will keep water off the foliage and blossoms and prevents leaf spots. (Courtesy of Missouri Botanical Garden Plant Finder)