The Gardenia is native to the Far East from India through to Japan. Its creamy white flowers are very fragrant, and necklaces of them are made and offered to local divinities, and strings of them tied to maidens hair. Gardenia jasminoides is a small shrub with greyish bark and dark green shiny leaves.
Styles & Sizes: They create a dense medium to large bonsai in almost all styles, but are by far they are most popular as informal upright and broom styles. In these styles, the crown is allowed to volumise, allowing the flamboyant white flowers to show off.
Position: In the temperate zones they are best grown indoors in a warm conservatory or heated greenhouse. They need a lot of light and humidity, so situate in a bright spot but avoid exposing to direct midday sunlight if possible. If required provided addition artificial lighting in the long winter nights. Use a humidity tray to provide the high levels of humidity it needs, and ensure temperatures are above well 15°C every day. Ensure there are not-too-much temperature fluctuations.
Watering: Keep soil moist but not waterlogged. Water early in the morning to ensure the bonsai has enough when it needs it during the day and is able to use it up before nightfall. Overwatering and waterlogging can lead to chlorosis turning leaves yellow and falling off.
Feeding: Every two weeks during the growing season and every 6 weeks during dormant periods. Use a balanced organic fertiliser throughout the year and use and an additional dose or two of high nitrogen fertiliser in spring to help with the flush of new growth. They love an acidic soil so use an organic soil acidifier or teaspoon of vinegar to help keep the pH low and prevent chlorosis.
Repotting: Repot every 2 years in late spring when the warmer weather is well settled in. Use a rich well-draining soil of peat or loam, grit or sharp sand, leaf mould or bark all in equal parts by volume. Conversely, you can use a mixture of Akadama, Pumice and well-mulched bark in equal parts.
Pruning: Gardenia is best pruned after flowering in early summer. As they set they buds late summer in July for the next season, it is best to prune after flowering. Structural pruning is best carried out at this time too as this will effectively eradicate most or all the flowering buds. Cut back fully extended shoots to leave 3 active leaf nodes.
Wiring: Gardenia is best styled with the clip and grow method. If wiring is required it is best wired in autumn when the bonsai is dormant.