Mystery Gardenia , except in size, is similar to August Beauty; also, its blooms are very large.
All gardenias prefer warm, well drained soil. Blooms will appear in mid-spring and continue sporadically into early summer.
Ideally plant Westward facing area. Avoid Eastern Exposure. Gardenias do not like Morning Winter Sun
Photos (blooms) courtesy of Peter Hogg & Toms Creek Nursery in Denton, NC (foliage)