gardenia black leaves
My very large gardenia bush has developed a black,dull coating on most of its leaves. It does not rub off and is intermingled with white raised 1mm bumps. The bush is very healthy, with new growth. We live in HI and the bush is within 10 feet of a swimming pool. What is it anfd what do I do?
this is known as sooty mold (I live in HI too, and we have it on our gardenias as well
is our citrus, sometimes more, sometimes less). The white bumps are probably some sort of scale.
Even if some people don't agree with doing this, a mild soap (I use Ivory or Palmolive dish
detergent) mixed with water beats back the scale, though I have hardly ever managed to
get rid of it even on a single plant, as well as washing off the sooty mold. If you are in a
dry area (I'm in Hilo, so usually not dry) you may consider rinsing if off.