The Q&A Archives: "Black Spots On My Gardenia"

Question: I bought a variety of Gardenia from a local nursery. I cannot recall the name, but it was staked in a container and was suppossed to bloom white flowers. I put them in a container and put it on my front porch which gets a decent amount of sun. I used miracle gro potting soil and kept them sufficently watered but they never bloomed. The blooms would turn black and never open up. I tried treating them for bugs with Malathon 50. One died and the other is on the verge. They were about $45 each. The one that's still alive looks sad. What can I do?

Answer: The most common gardenia is the G. jasminoides or cape jasmine. It will grow in your gardening zone, given the proper care. Gardenias require a rich, very acid soil (pH 4.5 to 5.0). An abundance of moisture and high humidity is the most important factor in successful gardenia culture. Unfortunately, gardenia is often a disappointment to gardeners because it can be very, very demanding. For flower buds to form and thrive, night temperatures need to be between 60-65F. During the day, temperatures should be 70-75F. A very constant, even temperature is required or buds will drop. Bright light is essential, but avoid direct mid-day sun in the summer. Best of luck with your gardenia!

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