Should a Gardenia plant be pruned before bringing indoors for the winter?
Certified GKH Gardening Expert
Pruning a gardenia in the fall can reduce flower production the following year, as explained here:
If you need to prune it so that it will fit in its new location in your house, then yes, you can prune now without hurting the plant long-term. Here is more advice on keeping gardenias indoors: