Question
My Gardenia leaves have all turned brown and dropped off.  It was beautiful this spring.  Loaded with flowers.  Then in the last week 3 weeks appears to be dead.  My neighbor has the same issue with his Grapefruit & 1 Orange Tree.  Last year all of these had the black mildew on them.  I treated my gardenia with a fungicide and thought that it would be ok.  Is it truly gone?  I love it so much I can't make myself give up and take it out.  Any advice you can give would be greatly appreciated.

Debbie

Answer
Sorry for the delay in answering your question- very busy here.  Let's start with last year. The black mold was sooty mold and was caused by insects such as aphids, whiteflies and scale. The sooty mold is growing on honeydew or sugars left behind by the feeding insects and then the mold grows on it.  The mold is not harmful to the plant and will go away on its own if the bugs are controlled.   The scale is the most likely cause.  They are oval shaped and are probably the color of the branch bark.  They are closely appressed to the stems and suck the plant juices from the plant causing the defoliation of the leaves. These bugs can be scraped off with your fingernail. If left untreated they were probably around this year and have maxed out on the plant.  See if you have these bugs on the plant.  It may not be too late to salvage the plant.  This is what I would do if there is still some green tissue underneath the bark, which you can test by scratching with your fingernail.  If you find green or white tissue the plant is still alive, if you find brown tissue, then that part of the plant is dead and needs to be cut back to where you can find living tissue.  Then----- I would treat the plant with Bayer Advanced Tree and Shrub Insecticide.  This product is mixed with water and poured on the soil around the base of the plant.  It is taken up systemically and will kill the bugs within a week or so.  It also provides protection from reinfestation for up to a year.  I hope this fixes the problem.  Good Luck.