38a4f905_o_Grow_Gardenias_in_Containers__Remedies
[Symptoms] Yellowing leaves [Possible Causes] Alkaline soil or water, chlorosis due to trace element deficiency, underwatering, overwatering, insect pests [Remedies] 
Use clean rainwater, distilled water, or add 2 Tbsp of vinegar/gallon of hard tap water, use acidic fertilizer with chelated trace elements, keep soil evenly moist, check for pests and eliminate
How to Grow Gardenias in Containers
Remedies