Gardenia Plant Turning Black and Leaves Falling Off

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I am taking care of my sisters Gardenia plant and when I went to check on it today the leaves are wilting and turning black and falling off. Her land lady also checks on it and she fills the mister when the water runs out. My sister is in the hospital and has been in there since September. I have asked her landlady to leave it alone but I am not sure what is going on can you please help me save her plant. Thank you in advance. Paula


Dear Paula,

Gardenia Plant Has Black Spot Disease: There are several things that can cause black leaves and leaf drop on a gardenia plant, Gardenia jasminoides; but from your description, I think it sounds like Black Spot disease. Black Spot disease (Diplocarpon rosae) is a type of plant fungus. It usually attacks the lower leaves of the plant first, then moves upwards on the plant causing leaf drop and black spots all over the leaves. The best way to treat Black Spot disease is to remove all of the infected leaves and any leaves that have dropped onto the soil; keep the leaves dry at all times (stop misting the plant), provide good air circulation around the plant; and spray the plant with a commercial plant Fungicide. You canals use Neem Oil which is an organic, non-toxic, alternative for treating Black Spot disease. Whichever product you choose, spray your plant every 7-10 days during the warmest part of the day since the fungus is most active when the temperature is between 75° to 90°F. Keep your plant away from your other plants.

If the the condition gets worse, you may have to cut the plant down to just above the soil line and have it regrow. After you prune it all the way back, spray what remains with the fungicide or Neem Oil.

When healthy and being cared for properly, a gardenia plant gets lovely, beautifully scented, waxy, white flowers surrounded by green, glossy leaves. But a gardenia is a very temperamental plant and quickly deteriorates if the conditions inside do not mimic its outdoor growing conditions. This is a plant that needs a fertilizer and a soil for acid loving plants. The correct temperature is extremely important if you want the plant to flower indoors. The besttemperatures for a gardenia plant is 65°-70°F (18.3°-21.2°C) during the day and  55°-65°F (12.8°-18.3°C) at night ((10° cooler). Cool night temperatures are essential for the buds to set. Gardenia buds drop off if temperatures go above 70°F (21.1°C). You can read all my tips on how to care for a gardenia plant at: