Will the gardenia or the jasmine bush be good for the direct sun all year and will I have to worry about the cold weather at night in our winter months?
Gardenia and Jasmine Bush
Certified GKH Gardening Expert
While in many areas they prefer partial shade, gardenias can thrive in full sun depending on your location (hardiness zone). If your area is prone to very hot conditions during the peak afternoon, your gardenias risk scorching. The jasmine, too, likes full un but would likely benefit from afternoon shade in hot conditions. Also, the area should remain relatively moist. It would probably be best to locate them in an area receiving afternoon shade if conditions in your area are hot and dry. Otherwise, it should be okay to place them in the sun, giving them plenty of moisture.
As long as temps don't fall below 20 F for extended periods, both jasmine and gardenia can survive outdoors just fine. If it falls below this, they will need to come inside for winter. In your zone, both these plants should do well. I would, however, recommend placing them in a sheltered location for protection during any unusual cold spells. Also, in the event of frost warnings, you may want to cover it. Here is more info that should help: https://www.gardeningknowhow.com/plant-problems/environmental/frost-how-to-protect-your-plants.htm