If you are growing your Gardenia as a potted plant indoors, keep it out of direct, hot sun, and allow it to only get bright light. I think that your 'black mold' is more than likely an algae growth, which is a cosmetic problem for your plant rather than a health problem.
Monona is a city in Dane County, Wisconsin, United States. The population was 7,533 at the 2010 census. It is completely surrounded by Madison and is part of the Madison Metropolitan Statistical Area.
Mondovi is a city in Buffalo County in the U.S. state of Wisconsin, along the Buffalo River. The population was 2,777 at the 2010 census. The city is located mostly within the Town of Mondovi. A small portion lies within the Town of Naples.