I have a Gardenia tree in a pot. This summer I put a large dish under it so it would hold a lot of water while I was gone for weeks at a time. It loved it. It grew twice as large and the leaves looked healthy. Now all of sudden the leaves are turning yellow and the green leaves are all wilted no matter how much water I give it. Do you think I rotted the roots. Should I transplant it in a larger pot and redo the soil. I have used the miracle grow on it but not helping. Any help would be appreciated