Answer: Gardenias need at least a half day of full sun to bloom, but at the same time, the hot afternoon sun can be tough on them. Morning sun is best, so an eastern location would be ideal. You might also try a southern or western exposure with some filtered afternoon shade. Buds that turn black or drop and leaves with a reddish cast are sure that gardenia is getting too much hot sunshine. Leaf drop can also be caused by improper soil pH (gardenia require 5 to 5.5pH - on the acid side.) Yellowing and leaf drop are also signs of various soil nutrient deficiencies such as nitrogen, zinc, and iron. Finally, if the air is too dry, your plant will drop buds and leaves. Try sprinkling the plant every morning to increase humidity (and also discourage spider mites!). Hope these suggestions help!
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