Hard freeze; 19 degrees tonight

Last night there was some precipitation, so we had a little coating of ice; tonight the wet has burned off and it's just cold, cold. Brought in the lemon tree and my little bowl of violets (already covered with ice, but the ice vanished over the course of an evening -- sublimated? absorbed right into the leaves? there was no water on the counter!). Haven't checked on the roses. Hoping the brave little violets make it; actually, they look fine.