Gardenia jasminoides is a beloved plant for the simple reason that few natural scents are as remarkable and memorable. If not for this spectacular appeal, few gardeners would try to grow high-maintenance gardenias vulnerable to insects and diseases.
Gardenias, which are similar in appearance to Ixora, are a popular gift plant and almost irresistible when in bloom, but they are notoriously difficult to grow in normal indoor conditions. Nevertheless, even a few months with a blooming gardenia in the house makes them a worthwhile addition to your collection. The basic species features glossy green leaves and waxy, highly fragrant white flowers. Native to China, this plant has been widely cultivated, so there are many cultivars available. In warmer climates, where gardenia is grown outdoors, many plants are sold grafted on a Gardenia thunbergia rootstock. The grafted plants tend to be more vigorous, with better, larger blooms, but they are even less cold tolerant than the basic species.
Watering gardenia shrubs directly into a soil keeps foliage from becoming wet and diseased. Regular garden hoses, in-ground soaker hoses or sprinklers systems are useful. Drip irrigation systems keep water from falling directly onto flowers and foliage. These systems attach to outdoor faucets, allowing water to slowly absorb into soil and roots.
Avoid using heavy soil. It may be too compacted for your potted plant and won't allow air to get to the roots.
It is important to never remove more than a third of the foliage in any one year and to cut just above a node on the stem.
It's a good idea to repot your gardenia in the spring or every other spring as needed. If it seems to be pot-bound or not as healthy as it had been but you find no insects or diseases, it usually is a good signal that it needs to be repotted. Use a low-pH soil formulated for rhododendron or gardenias.
Plants that don't like a lot of moisture will need a drainage hole for moisture to escape and for airflow to circulate through the pot. Another important function of drainage holes is to allow water to flush the soil of excess salts from fertilizers.
