Few flowering houseplants prove as frustrating to the indoor gardener as gardenia. However, if you provide the proper light, humidity and temperature conditions, you can regulate the quantity, time and length of bloom.
FACTORS REQUIRED FOR BLOOM
The most critical factor in encouraging your gardenia to bloom is TEMPERATURE. Gardenias do not produce flower buds at evening temperatures above 60 to 62 F. If the night temperature is kept at 60 to 62 F, the plant will bloom continuously.
Also essential to flower production is sunlight. In fact, the number of flowers on a gardenia is directly proportional to the light intensity. When you grow a gardenia in the shade, its leaves are thin and weak producing insufficient plant food to develop flower buds.
Finally, gardenias like a high relative humidity. In a greenhouse where water is splashed about or mist systems are often installed, this is no problem. In your home, air conditioning and heating units decrease the relative humidity, often resulting in bud loss. You can counteract this problem by setting the pots on trays of moistened pebbles, peat moss, sand, perlite or sawdust.
Fertilize your gardenia monthly with Jack’s Classic® Houseplant Special 15-30-15. For hard water or to lower the pH of your soil, try Jack’s Classic®
Acid Special 17-6-6.
Choose one of the following application rates:
- ½ Teaspoon per gallon of water every other week OR
- ¼ Teaspoon per gallon every time you water your plants.
Note: You can use a 1 gallon empty water/milk container to make your fertilizer solution. Water as directed. Store the rest for later use.
KEEP THE SOIL MOIST
Without continuous growth your gardenia will stop blooming. If it dries out between waterings or becomes soggy, your gardenia will drop its buds first and its older leaves a week or so later. You can make a good well-drained potting mix from 2 parts peat moss, 1 part coarse sand or perlite and 1 part potting soil. During prolonged cloudy weather supplement natural lighting with a grow light.