Yellowing leaves usually mean too much water not enough sun as well as soil deficiency. About a week before transplanting gardenia bushes prune the branches back by one-quarter or one-third. Plant Guide Gardenia Bees And Roses Gardenia Plant Plants Plant Guide Mist daily with bottled water and do not water the plant for about a month if you think you may have some root rot happening. How to revive a dying gardenia . How do I keep gardenias from turning brown. At the first sign of tree sickness consult an arborist right away. Provide extra moisture with daily misting set the plant on a tray of moist pebbles andor use a humidifier. If you have some root hormone or root stimulant like DynaGrow K-L-N add some to the soaking water. First I soak the plant thoroughly for an hour or two before repotting. If all of a sudden life leaves Gardenia and your bush is turning yellow shedding its foliage determine the reason as soon as possible and try to save it. Salt burns the r...