Your gardenia bonsai needs to receive bright indirect or diffused light or up to four hours of direct sunlight each day for best flower and foliage growth. During its active growing season, spring through fall, daytime temperatures of 70º to 85ºF. and night temperatures 55º to 65ºF. are ideal. During winter, temperatures may drop to 45ºF
Since your bonsai will need extra humidity, place it near other leafy plants, or next to an open container of water, or in a decorative tray filled with pebbles and water. (Do not allow the water to touch the bottom of the planter, however, or the plant will be over watered). Misting the leaves frequently will also help to raise the humidity around your gardenia.
It is beneficial to move your gardenia bonsai outside to a semi-shady spot after the danger of frost has passed. The soil will dry out more quickly outdoors so pay close attention to watering requirements. The bonsai will need to be brought indoors each fall before temperatures drop below freezing.
Keep the soil evenly moist but never soggy. In warmer weather, you may need to water every other day or more. You can tell when the plant needs water by the color and feel of the soil surface. The soil color lightens as it dries and the surface feels dry to the touch when it needs watering. After watering, when the soil surface is moist, the soil color is a deep chocolate brown.
To water, place the plant in a pan with 2” of water and soak for twenty minutes or more until the soil looks and feels moist. Never allow the soil to dry out completely, but if it does, immerse the entire pot in water for five minutes or until the soil is thoroughly wet. Do not use water that has been treated by a water softener.
In early spring, cut back long, unbranched growth to keep your plant bushy. Make the pruning cut just above a leaf joint. Throughout the growing season, pinch out the ends of some of the branches to produce a fuller plant. Since gardenias set flower buds at the ends of the branches, allow some branches to grow out unpinched. After flowering, you may prune these branches to shape your plant.
Apply an acid-type fertilizer (such as an azalea/camellia food) at half strength once a month from spring to fall. If new leaves are yellow with green veins, apply an iron chelate fertilizer, obtainable at your local nursery.
Plant material, such as this product, should not be eaten. While most plants are harmless, some contain toxins.
Gardenia flower buds are very susceptible to dropping off before blooming. There are several causes of premature bud drop: over or under watering, sudden temperature changes, night temperatures over 70° F, and insufficient light. Lack of adequate light or allowing the soil to dry out excessively may also cause some older leaves of your gardenia plant to turn yellow and drop off.