Allan,
With your winters Id def seal her. You dont want any bacteria or rot setting in. Id clean the cut up a bit with a sharp 1 sided razor, grafting knife or box cutter. Give her a straighter edge. U can seal her with Pruning sealer (looks like tar and is messy), Dap in Almond, clear or brown colors, if not you can use wood glue also.
I know some people use lime paste to seal or even wax, so basically what ever you have or are willing to run out and get will do.

Good Luck.

totally agree. when my info was torn off 2 days ago, I ran out and covered it with L.E.T....esp. since finally rain is coming. roxanne

Thanks for the advice guys. I guess i will seal it. It's better safe than sorry.