Switching from buckets to Shurflo on solar vacuum help

[DrTimPerkins]

Sap still flowing at under 32 F? I didn't know that could happen. I guess I still have alot to learn about maple tree physiology.

It's quite simple. Air temperature and tree temperature are not always the same thing (and frequently are not). Air temperature can change rather quickly...tree temperature is buffered and thus changes more slowly and unevenly (not surprisingly considering the tree is about 70% water). Not only is there a difference in temperature between air and the tree, there is considerable variation in temperature even within the tree. South sides of trees and fine branches will thaw faster (especially if it is sunny), north sides and larger branches will thaw more slowly.

It is somewhat more common for sap to stop flowing on tubing systems because the tubing freezes than because the tree freezes. Different portions of the tree may be thawed and exuding sap while other parts are freezing and taking up water (from the soil) at the same time.

https://www.themaplenews.com/story/w...ly-season/362/