Gardenia Plant Zones

Plant Zones

• Native to Japan, China and Taiwan, the gardenia is a warm-climate evergreen that grows best in U.S. Department of Agriculture plant hardiness zones 8 through 10. In USDA zones 8, 9 and 10, you can grow a gardenia outdoors year-round. When planting in the ground, it is safest to wait until fall or spring, though where it is hardy it will likely survive planting at any time of year. It can also be grown as a houseplant everywhere.

Temperatures

• A gardenia likes moderately cool temperatures, around 65 degrees Fahrenheit during the daytime. As that is a little cooler than room temperature, it will do best by a window that will cool it off if you grow it inside during the summer. Nighttime temperatures should stay above 55 F, so a gardenia may not do well outside on the lower end of the hardiness range in USDA zones 8 and 9.

Humidity and Moisture

• The gardenia does best in a humid climate and may suffer in a dry climate. Abrupt changes to the amount of water it gets can cause the loss of buds and blackening of the leaf tips. Once well established, a gardenia is somewhat drought-tolerant. Inside, it is important to maintain proper humidity. You can run a humidifier or group plants together on trays of wet pebbles to increase humidity.

Culture

• A gardenia will grow well in sun, semi-shade or shade. It will tolerate clay, sand or loam soil, preferably slightly alkaline, and prefers the growing medium rich in humus and well-draining. Don't plant a gardenia too close to other trees or shrubs, as it will not fare will with the interference of its roots. Space gardenias 3 to 5 feet apart when growing them as a hedge or in a group. Spread mulch or compost around the plant to provide nutrients.