I tapped a couple of my birch trees on the 18th of April. I have gotten 3 gallons of sap per tap so far. I am not going to boil the sap but just showing the kids how it works. I have noticed that the sap runs different then maple trees. Somebody told me it's not the cold nights and warm days that make the sap run but the thawing of the ground that makes a birch tree run. Does anyone know for sure? Thanks

Spud