Q: I have a ten year old river birch which has been steadily dripping a clear, odorless, tasteless (yes, I did) liquid from two branches for several weeks. Do you know what this is? What can I do about it?
A: River birch tree sap is known to cause babies to be born naked and to make your hair turn gray when you’re old. Other than that, the sap that is dripping from the cut branches is harmless. Maple and birch trees are famous for the copious amounts of sap they bleed after being pruned in late winter. Once, when my father delayed pruning his grape vines, he measured a pint of liquid that trickled from a cut vine. Sapsuckers (a type of woodpecker) take advantage of the slightly sweet nature of the tree sap and tap dozens of shallow holes in the bark of pecan, maple and magnolia trees each spring. Neither their pecking nor the bleeding does any harm to the tree. Your birch tree will gradually stop dripping as spring proceeds. If you want to perform an interesting experiment next February, prune any maple and birch trees you own and collect the sap as it flows. Boil it down like New Englanders do to make syrup. Your efforts might yield a half-cup of sweetener from a gallon of sap.