Q.I missed the best time to prune my gardenias. Should I prune them in late September or wait until next June?
The picture and this comment are here because the site keeps asking for more information so I made sure there was something in each box.
Certified GKH Gardening Expert
As long as it is not setting next year's flower buds right now, and you have caught it before, then it is ok to prune now.
If, you notice new bud growth, then it will be too late and pruning will inhibit flowering next year.
this article will offer more information: https://www.gardeningknowhow.com/ornamental/flowers/gardenia/when-to-prune-a-gardenia.htm