I live on the Sunshine coast in Queensland and have some very large straggly gardenias in my garden that have not been cared for. They always have yellow leaves and never look any good. After reading lots of information, I now know how to care for the yellowing but was wondering if there would be any benefit to prune to about 30-40cm above the ground, fertilize, ensure plenty of water and hope they come back. Could this heavy prune have any benefit?
Certified GKH Gardening Expert
While some plants do respond well to this kind of heavy pruning, gardenias are not one of them. Instead, I would focus on pruning to improve air circulation by removing branches that are growing very close together are rubbing up against each other. Gardenias can only tolerate about 1/3 of the plant being removed a year. More than that, and it can kill them.