How to Care
Appropriate location and frequent care are crucial to the survival and health of a gardenia plant as they are highly sensitive which makes them hard to grow.
Choose a planting location with bright sunlight and low salt content in the soil. The pH of the soil should be below 7.0. If you cannot get he soil right outdoors or in the ground, gardenia will grow well in containers and in humid sun rooms.
Amend the soil (if planting in the ground) with peat moss or compost to improve drainage and nutrient capacity.
Dig a hole in the ground as deep as the root ball and twice as wide. If planting in a container, fill the bottom of the container with soil formulated for container gardening, leaving enough room for the root ball to be inserted in the container.
Place the root ball in the hole. Fill in the space around the root ball with soil, while holding the plant steady. Gardenias don't respond well to root disturbance; take great care to ensure that the roots are not injured during this process.
Mulch around the base of the plant using bark or wood chips, leaving a 2- to 3-inch radius around the base of the plant free of mulch. Water the plant well.
If you are container planting, place the container or pot on a tray of wet pebbles to increase the humidity around the plant.
Feeding and Watering
Water indoor gardenia once a week, and outdoor gardenia as often as needed to maintain an even level of moisture. Check outdoor soil frequently for moisture content, by inserting your finger into the ground at a depth of 1 or 2 inches. Water outdoor plants more during periods of dry weather, and less during periods of wet weather. Water from below and avoid wetting the leaves.
Fertilise a couple of times a year using an acid-loving fertiliser. Use a fertiliser formulated for container gardening for indoor plants.
Prune the gardenia with sharp pruning shears after the blooms fall from the plant. Cut away dead wood and reduce the plant to desired size.
Pests and Diseases
Check plants frequently and regularly for pest problems. Gardenia plants may become infested with spider mites, aphids, scales and white flies. Use insecticide on an as-needed basis.