I have a gardenia in a south window that has been lush and green since August when I brought it in. It had thrown 4 buds in December (none of which have bloomed as of yet) and all of a sudden the leaves started turning yellow and dropping off. There is no sticky stuff, no spider mites, no mealy bugs, nothing that I can see or feel. I had been giving it Miracid in a very weak solution every watering. Thinking that I had burned it I have flushed the soil out for the past 4 weeks, but the leaves still are turning yellow. What's up? Anything I can do to save it?