Infestation of Gardenia Plant

Asked June 15, 2015, 2:10 PM EDT

Dear Experts, I received a gift of a lovely gardenia plant over 20 years ago. It lives in our living room close to a big window. It is still healthy and is now about 4 ft. tall and its leaves are 2 and 3 inches long. It had a few beautiful blooms in April. But a few weeks ago I noticed tiny (smaller than a pin-head) light brown spots on the leaves, both sides, and on the stems, too. Over several days the spots grew in number, became 3-dimensional, about pin-head size and gradually turned dark brown. Along with that there were little clear spots of a sticky substance in different places on the leaves and stems. I decided one day to remove all these brown egg-shaped things and clean off the sticky areas. I had never seen this before on my plant. I used wipes (without alcohol) and sometimes I used just a wet paper towel and scrubbed off every leaf. The plant seemed happy and kept growing. Then I noticed these little brown things and sticky patches on a neighboring plant. And after a few days the little brown things came back to the gardenia plant "with a vengeance" along with the sticky stuff. I cleaned them off again. Then we put the plant outside on our balcony, hoping that if the brown things were eggs that they would hatch and the insects would fly away. I am wondering if the little "fruit flies" we see in our home sometimes are being hatched on our plant. I love our gardenia but don't want to have a hoard of these insects in our home. What can I do to take care of this problem? I used to use fertilizer regularly but haven't in awhile. Never pesticides. Thank you for considering my question! -Sylvia

Anne Arundel County Maryland houseplants scale insects gardenia fungus gnats

1 Response

From your description it sounds like like you may have scale insects on the gardenia. They are sucking insects and as they feed they excrete a honeydew which fosters the growth of a sooty mold. Scale insects are not easy to control. Look at photos on our website for more information and control. http://extension.umd.edu/hgic/scale-insects-houseplants

The flies that you see in your house may be fungus gnats or white flies. You will have to identify.
Fungus gnats breed in moist potting soil. If the fungus gnats are breeding in potting soil, dry it out. When the soil dries, the larvae will die. Change the watering cycle of the houseplants to prevent the soil from remaining wet. http://extension.umd.edu/hgic/fungus-gnats-houseplants

White flies - http://extension.umd.edu/hgic/whiteflies-houseplants
See the attached link on care of gardenias iindoors http://www.agriculture.purdue.edu/agcomm/newscolumns/archives/YGnews/2004/December/041216YG.htm
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