Q.What am I doing wrong with my gardenias?
I’ve recently moved to Hutto Texas and I’ve tried growing gardenias three different times. Each time the plant stems start turning black then it moves to the leaves and it within a couple days to plant is gone. I’m an avid Gardener I grow most things from seed. I just don’t know what I’m doing wrong with my gardenias. They are my favorite flowering bush and I want to succeed.
Gardenia are a finicky plant! You are not alone in frustrations in growing Gardenia.
The black leaves could be due to root rot or even Sooty Mold that is caused by pests.
These links will help you review the care needed.
https://www.gardeningknowhow.com/ornamental/flowers/gardenia/gardenia-plant.htm
https://www.gardeningknowhow.com/ornamental/flowers/gardenia/common-gardenia-diseases.htm
https://www.gardeningknowhow.com/ornamental/flowers/gardenia/fertilizing-gardenias-in-your-garden.htm