Gardenia Jasminoides - Cultivation

Cultivation

It is widely used as a garden plant in warm temperate and subtropical gardens. It can be used as a hedge. It requires good drainage and a sunny location, and prefers a acidic soil with a pH between 5 and 6.5.

Gardenia jasminoides is generally considered to be somewhat difficult to take care of.

As a subtropical plant, it thrives best in warm temperatures in humid environments. Getting those conditions is rather hard in temperate latitudes, the reason for which gardenias are usually cultivated as houseplants or in greenhouses. In warm places, though, it can be grown outdoors. Either way, it prefers bright indirect sunlight or partial shade.

Apart from the difficulties in creating suitable conditions for the plant to live, gardenias need to be planted in an acidic soil (it is a calcifuge). If the soil is not acid enough, many of its nutrients (especially iron compounds) will not be available for the plant, since they will not dilute in water and therefore will not be absorbed via the roots. It this happens, gardenias start to develop chlorosis, whose main symptom is a yellowing of the leaves. (See Soil ph).

For this reason, it is advisable not to water gardenias with very hard water. When having to water with hard water, it is possible to add some vinegar or lemon juice to it before doing so, this will lower the pH of the water.

Iron chelate can be added to the soil in order to lower the pH, but care must be taken since an overdose can kill the plant, as with any other inorganic soil amendment.

Some gardeners will spill vinegar over the soil to effectively keep the pH low and prevent chlorosis. This can be carried out either regularly or when the first symptoms of chlorosis have been spotted.