It's in May that the gardenia bushes burst into bloom and the air smells divine. I'm always amazed by how well these usually chlorotic shrubs do in our limestone soil. Traditionally, to keep them happy, one pours pickle juice and other acidic food waste around the roots. The simplest thing to do, really, is mulch them well.
Still, I keep my gardenias in large pots and water them from the rain barrel to avoid the problem. Even so, I've lost them from other diseases over the years. They tend to be a bit finicky in their needs.
My favorite bloomed throughout the winter, and wasn't even phased by the freeze. Extraordinary!
I also have a trailing gardenia. It's more of a curiosity since it's a very slow grower and the small flowers don't have a particularly strong scent. It's nice in a big ceramic pot and helps disguise the rain barrel.