My soil ph is 5.5, which should be suitable for gardenias. Always having a problem with yellow leaves. I fertilized them this spring and treated them with liquid iron, but still have yellow leaves. Any suggestions? Thanks, Mike Davis
Yellow Gardenia Leaves
Certified GKH Gardening Expert
It sounds like you are feeding your gardenias well, so it's probably something else. Watering problems can cause a gardenia's leaves to turn yellow. Overwatering or poor drainage in the soil could be the culprit. Or, you might not be watering enough during dry conditions.
Root rot can cause yellowing leaves. This is caused by fungi, but is made worse by overwatering or poor drainage: