If the buds are not open on the cherry tree they should be OK. (a sheet wouldn't hurt though) We had 28 degree temps here this morning, with a high only up to 38. A few snow flurries as well, but nothing to big. Supposed to get colder. My sweet cherry is in full bloom, and so are my apricot trees. They will be toast, as it's supposed to be freezing for the next 3 nights here.