Gardenia from exotic China. Therefore, in our conditions is very demanding. You correctly guessed that she needed a certain temperature.
The optimal conditions for home gardenia are 18-22 (degrees of heat, in winter, in the extreme case, not lower than 16 degrees, otherwise the tied buds may not open and fall off.
In general, it is not accustomed to distinguish between summer and winter, so she needs a stable temperature regime and shading from the hot midday sun.
Now smoothly turn to watering the gardenias.
Watering the flower gardenia should be regular, she does not like the drying of the soil, or waterlogging. At the same time, once a month, the water should be slightly acidified with citric acid. During budding, gardenia should be sprayed, and the pot should be placed in a pan with wet moss or peat, since it is important for the increased humidity of the air.
When the flowers of gardenia begin to unfold, Spraying can be stopped so that no brown spots appear on them. Flowers are at the ends of annual shoots, so after their wilting, shoots must be shortened.
Top dressing gardenia prefers from spring to autumn two or three times a month. If it is mineral fertilizers, it is better to take such that they do not contain calcium. It is very sensitive to a lack of iron, for this reason the leaves become whitish.
It can be helped by pouring water with the addition of ferrous sulfate (one gram per liter of water). In gratitude for the care of jasmine gardenia dissolves the flowers of an amazing fragrance, from which the room is filled with a magical fragrance.
Blossoms gardenia jasmine from May-June to September, but before that it needs a rest period of four to six weeks. At this time, water it should be small, otherwise the buds will get a wrong development.
In frequent transplants this gardenia flower does not need, except for the purpose of a slight increase in the size of the pot. The soil loves an acidic, consisting of turfy ground, humus, peat and sand, taken in equal proportions. For propagation of gardenia, only apical cuttings are suitable - half-ripe, that is not soft, but not lignified.