Seasonal Vernacular

     It snowed here yesterday.  But it wasn't just any snow.  It was the onion snow.  That's a colloquial expression used by locals in certain parts of Pennsylvania to describe the final snowfall of the season that typically occurs after the spring onions have been planted.

     The onion snow always falls after Kunigund Day, March 3, when the frost will go no deeper into the ground and after St. Patrick's Day, March 17, when peas and onions are supposed to be planted, according to the editorial staff of the York Daily Record in York, PA.

     My question is, how do you know it is really the last snow of the season?