Answer: Since you have quite a lot of experience with your gardenia, taking it indoors and out depending upon season, I'm sure you're familiar with its behavior when it is first moved. Typically, when taken from outside in, where the light is less intense, the foliage can turn yellow and fall off. It can also act that way when temperatures and humidity are different than it had been recently experiencing. I understand why you wanted to take it indoors to get it out of the wet weather, but perhaps a better solution would have been to simply move it under an eave or patio covering rather than take it indoors. But, now that it is indoors I suspect you'll keep it inside for the winter months. If so, I would repot the plant in fresh potting soil, removing any damaged (or soggy roots). Then cut the plant back by about one-third, both to remove the unattractive foliage and to encourage new growth. Set it in a bright spot - where you normally keep it during the winter months.
I hope it recovers soon!
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