There are a lot of people out there that have no luck with growing gardenias but then there are still those few that have very good luck with growing gardenias. Sounds to me like you have some magic powers when it comes to growing plants. At least when it comes to plants that no one else can grow. Let’s first agree that although these Gardenia flowers sparkle like moondust with their pure white petals, although they send off a thick unforgettable fragrance so enchanting it goes right into perfume, growing them is pure science.
When growers cultivate these, they must know what makes them grow and what makes them flower, because those are the Gardenias that will fly off the shelves. You can use what they know to become a better Gardenia Gardener.
There is a report that some scientists put out on the study of gardenia plants it is called, "Flower Initiaition and development in gardenia plants as affected by photoperiod and night temperature." What scientists E. P. Makridou and A. S. Economou did was expose Gardenias just like yours to different daylengths: eight, 12 and sixteen hour days, for four weeks. Then they took all the Gardenias and exposed them to sixteen hours of daylight for four more weeks. Which Gardenias do you suppose had the most flowers?
The ones that began with eight hours of light, the ones with 12 hours of light Or the ones with 1sixteen hours of light? Turns out that the Gardenias that had the shorter days, and then switched to longer days, had the most flowers of all. The researchers concluded that ‘short photoperiods promote flower bud initiation in Gardenia plants. But that’s not all! They did another experiment.
This time, they exposed all their Gardenias to eight-hour days for four weeks and then split them up into three groups. These pots were now grown under different daylenghts eight, 12 and sixteen hours long. Guess the results for this experiment. Did changes in day length affect flowering? Answer: The ones that had long days for a full eight weeks and the days that were sixteen hours long flowered quickest. Then they did another test!
They wanted to know if night temperatures would have any effect on Gardenias. So they grew them all with eight hours of daylight and set the thermostat at 75 degrees F. When the lights went out, they lowered the temperature to while the night temperatures were kept at 55, 65 and 75 degrees F.
They did this for four weeks. Then they chaned the night temperature. All Gardenias were now spending their nights in a 65-degree F room. They did this for four weeks. And they tried several other combinations of temperatures as well, all with the same eight hour day length.
Results: Gardenias flowered earliest when exposed to days and nights of 75 degrees F. All the Gardenias flowered. There was no other effect observed on the number of flowers. So if you want to use this research, you would want to give your Gardenia only eight hours of daylight for four weeks. Then you would make the day longer. You would give it sixteen hours of daylight. This Gardenia would have constant temperatures of 75 degrees F the whole time. And you would have Gardenias coming out of your ears.
If you put your Gardenia outside, you know it’s going to get Aphids. But this is not a problem! Because you are going to run down to the Garden Center and pick up a nice big container of Ladybugs. Spray them with Sprite before you put them down. That will keep them from flying away. Sprinkle them around your Gardenia, in the middle of your Garden. If you have Roses, you can put them in the same area, and the Ladybugs will run around your garden hunting for Aphids, Mealybugs, Beetle larvae, ants, all kinds of insects you never knew you had.
No fuss, no muss. And you can get up close and personal with your Gardenia, you can eat your Gardenia, and there will be nothing poisonous there to make you sick. I love that most of all. If you keep your Gardenia potted, it will most certainly dry out very quickly. Growing one of these is not like growing them indoors. The great outdoors is full of surprises, and these Gardenias do not take dry soil kindly. Watch it very carefully if you do that. I do believe however the fresh air is good for everyone after a winter indoors.
They’ll study that someday, but for now, it’s my personal theory. Remember that humidity is always important for these plants, that a low pH is their comfort zone, and that when moving anything to a full sun exposure you should do it gradually to give leaves time to adjust their chlorophyll. If not then as I have said go to your local nursery and talk to them about your gardenia or you can go on the internet and do a search for gardenia and see what you come up with.