After purchasing a bush gardenia, is it wise to transplant when it is still blooming? Should a bush gardenia be transplanted from a small pot to a bigger pot when it is in the budding stage?
Transplanting Budding Gardenia
Certified GKH Gardening Expert
If possible, I would wait till after the plant has finished flowering (if it does). Here is an article or two that you may find helpful about transplanting gardenias and repotting (directions for repotting houseplants would be the same): https://www.gardeningknowhow.com/ornamental/flowers/gardenia/transplanting-gardenia-plants-planting-gardenia-somewhere-new.htm
Repotting plants as soon as you purchase them is not really necessary, or recommended. The grower has used good soil and fertilizer to optimize growth. Also, the plant will grow roots first and fill the pot with them, before it attends to leaves or flowers. You don't need to repot unless the soil is so full of roots it won't hold water, or the plant is falling over, or you want to grow it bigger.