If it is wet, as long as the temps weren't at 30 for a long time, I wouldn't think you would have a lot of damage. Especially with it being wet. If they were wet when it froze, they should have had a layer of ice form around them. Once the ice is formed, the temp of the ice will hold at 32, and keep the colder outside air from reaching the plant. A lot of plants can live through32 for a while.
However, they can't live through 28 or lower for very long. Low spots are real bad about that. If there isn't any wind, the coldest air will settle in them, making them 5-10 degrees cooler than the surroundings.[
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