Rising of the sap

With temperatures this week predicted to be consistently above freezing during the daytime, below at night, we have the perfect conditions for sap movement in sugar maples here in southern Maine. Personally, I am a great fan of the light amber syrup, the first run syrup which seldom makes its way into the grocery stores--I buy it at Ted Greene's sugar house in East Sebago, but you have to get there before Maine Maple Sunday.

Last year, I put a tap on this sugar maple at the corner of Willis and Melbourne Streets here on Munjoy Hill. It took constant attention from two households to keep our collecting buckets--milk jugs--from overflowing. It took a lot of hours to boil the sap down to so-so syrup on the stove, with the primary beneficiary being Northern Utilities. This year it's Ted Greene's for me.

Though it's about ten degrees colder in Vermont than it is here, you can click on this link to track the movement of the sap at the University of Vermont's Proctor Research Center website, where they have maple trees rigged up with temperature and pressure sensors. Not incidentally, the sensors track the reverse of dormancy, as they monitor temperature in twigs--the first to unfreeze--trunk, and ground, along with the sap pressure in various locations (sunny side of the tree, shady side). Also tracked is air temperature, and if you check during the day, you can see how midday temperatures affect the tree's metabolism. All in all, this site is a treasure for plant geeks. And it reminds us the best days of winter are just ahead.