I hope you find this helpful! https://www.gardeningknowhow.com/ornamental/flowers/gardenia/gardenia-plant.htm
And here is how to do some cuttings! https://www.hometalk.com/33110181/growing-gardenias-from-cuttings
Fall or spring is the most suitable time for planting the gardenia bush. As for outdoor gardenia care, you should keep in mind that when the gardenia plant is grown outdoors, it generally prefers to be kept in partial shade. Gardenias also prefer moist, but well-drained acidic soil with plenty of organic matter.