Hardy in more temperate zones, I grew them in zone 7 near Atlanta but knew that during the coldest winters they might be killed to the roots. One of the most frequent questions from someone who has planted a Gardenia is about the yellowing of leaves. If the leaves have dark veins, the plant is trying to tell you that it needs feeding, or more water. If the leaves are an all over dark yellow, it either got a little dry or commonly in the springtime old leaves are making way for new.
This is a a senescent leaf, about to shed.
Note the all-over dark yellow leaf color. The leaves around it are dark and healthy.
Epsom Salts are frequently advised for Gardenias. If the plant is small, it doesn’t need a half cup of Magnesium Sulfate. A teaspoon might be more than necessary.
Here are some links to great advice on choosing and growing Gardenias.
MG336- Growing Gardenias in Florida -- University of Florida
HGIC 1065 Gardenia - Extension - Clemson University – South – Clemson University
Gardenias- A Fragrance That Captivates - Southern Living
I grow an old cultivar that might be ‘Mystery’ or ‘August Beauty.’ It was here when I first visited here more than fifty years ago. The old plant remains and I’ve rooted dozens of which I kept 15 for
my own garden and gave away the rest.
I have a florist’s gardenia from my brother’s funeral. I repotted it last summer and it still wilted without twice daily watering. I put it in yet a bigger pot and kept it through the winter in the greenhouse, where it languished. Come warm weather, I fertilized it, gave it a sprinkle of Epsom and planted it outside where it is now blooming and the leaves are beginning to green up.
Needs feeding, chlorsis of the leaves indicate deficiencies.
Almost forgot propagation. The way my Mother-in-law and others did it was to put a cutting in a Coke bottle, usually beginning as a cut flower and then keeping the stem and leaves when the flower faded. It takes a few weeks sometimes, but eventually there is a good rooted specimen if you started with a good cutting. They will root in soil as well without special attention. I’ve done both. If you want to use hormone powder and a misting set-up,that would be nice but they’ll root without it.
Gardenias make a nice evergreen hedge in Southern gardens. I usually just use three to link taller shrubs and trees. Pruning is best done as they bloom, taking flowers for bouquets or to float in a bowl of water.
The walk to the mailbox is pleasant when Gardenias bloom.
I joined the Fertilizer Friday meme at Tootsie Time this week. Gardenias point up the importance of fertlizer.