Answer: The steps you'll need to take to protect your plants really depend upon whether the plants are out in the open, or close to a fence or building (where they will be somewhat protected). Plants with new growth are especially susceptible to freezing temperatures, but those that are dormant will probably come though without problem. Camellias are generally hardy down to 20F, but gardenias are not and will definitely need protection. The graft on your rose bushes should be protected (pile up a thick mulch to cover the graft and keep it from freezing. I'd cover everything possible with old sheets or tablecloths, just to be on the safe side.
Best wishes with your garden!
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