Growing Gardenia
Latin Name Pronunciation: gar-deen' ya
Gardenia is a genus of about 200 tropical and subtropical, broadleaf evergreen shrubs and small trees with distinctively fragrant, white flowers. They need rich, moist, acidic soil that is high in organic content, along with a bit of light filtered shade in hot areas. Gardenias are hardy to Zone 8, but in colder climates your Gardenia may be overwintered in a container indoors, if provided with sufficient light, humidity, and attentive watering. The buds on your plant should open in 4–6 weeks. Flowers open white and mature to a soft creamy yellow, most lasting 3–8 days. Like other moth-pollinated flowers, they are more fragrant at night.
Growing Outdoors:
Light: Grow in sun to part-shade, supplying filtered summer shade in hotter areas.
Soil: Gardenias require moist but well-drained acidic soil that is rich in organic matter.
Watering: Keep plants consistently moist but never soggy. Water deeply when soil feels dry to the touch an inch or two below the surface. Plants will need more water in the hottest weather, less in winter, unless normal rainfall is absent. Mulch to preserve soil moisture and insulate roots.
Fertilizing: Fertilize monthly from spring until frost with a formula specific for acid-loving plants. Compost is always beneficial.
Pruning: When the flowers start to brown, they should be removed. Gardenias set their new flower buds in fall, so prune just after the last flowers have faded. Frequent pruning is not necessary but if you wish to shape, reduce the size of the plant, thin out the center to improve air circulation, or remove crossing branches, remove no more than 1/3 of the plant. Dead or damaged branches can be cut at any time.
Pests/Diseases: Monitor for scale, whiteflies, aphids, mealybugs.
Overwintering Indoors:
As fall approaches, move your potted Gardenia into more shade for a few weeks to help it adjust to lower light levels indoors. Inspect for insects and treat appropriately. Flood the soil and let it drain to flush out possible hitchhiking bugs; hose off with a good strong spray of water before moving the plant inside. When weather warms in spring, move outdoors into shade, then gradually into more sun.
Light: Provide 6–8 hours of direct sunlight such as can be provided by an unobstructed south or west window.
Watering: Gardenias enjoy potting mix that is slightly damp to the touch, but not soggy. If the potting mix gets either too dry or too soggy, flower buds may drop off.
Temperature: Gardenias perform best in a room that is warm by day (70-75°) and cool (60° minimum) at night.
Humidity: Gardenias are tropical or subtropical plants that appreciate high humidity. Avoid heat vents and cold or hot drafts. The best way to increase the humidity around your plant is to run a humidifier nearby or use a pebble tray. Misting the gardenia plant is not recommended.
Fertilizing: Fertilize Gardenias every 4 weeks only during their growing season (April to October) with a water-soluble fertilizer formulated for acid-loving plants or use White Flower Farm’s All-Bloom Fertilizer. Do not fertilize in winter.
