Plant garden on Mothers Day?

With the temperature on the farm below freezing for more than 4 hours last night, the Mothers Day date didn't hold this year.  And it's supposed to be colder tonight.  Frost is one thing, but freezing temps for that long are something all together different.  Our apple trees for the most part are at 1/2" green tip and tight cluster.  For tight cluster, at 27F for 30min a 10% loss is expected.  At about 6' high (where our weather station sits) we were down below 29 for about an hour, but our weather station in the high tunnel said it hit 27F and that is one foot off the ground.  Chances are we had 27F for quite a while at ground level.