Question
Hi, I have two gardenias that have the new growth turning brown and other leaves a slight yellow and then turning dark brown, curling and falling off.  One bush has just about lost all its leaves.  It is happening fast and looks like it has spread to another gardenia.  Any help?

Answer
Carmen,

I would advise you to check for Aphids or Scale first by looking at the undersides and the stems of the plants.

Poor drainage in the area or the after effects of being flooded out could have also possibly caused this type of damage. Check to see that the soils are draining properly by keeping an eye on it during rains.   

The only two diseases that I know of that attacks these plants, powdery mildew and phomopsis, cause different types of damage than what is described here.

I would recommend spraying them with a Horticultural oil and fertilizing the plants to stimulate new growth this spring.

Good luck,
Ed Gulliksen