I had 28f and frost on the roof, but not on the ground, so that's good. All kinds of plants think it is spring right now, so the large azaleas, pink tabs, and even some if the peach trees are flowering right now. Most of the flowers weren't damaged, so the duration must have been very short. Besides, many times in my location, when it is only around 28 degrees, the temperature can be 3 or 4 degrees higher at 6 feet above the ground than it is a foot above the ground. When it got 15f about 4 years ago, the temperature was only 0.2 degrees different at the same difference in height.
Anyway, most everything around here did fine, but I am lucky I have greenhouses to put my more tender plants in.