Number of dormancy days

[SyrupHog]

Anybody know if there is a "rule of thumb" for how many days a maple tree should experience freezing temps during a winter season prior to tapping? I'm thinking of tapping earlier this year (located in Eastern Ontario, Canada), sometime around mid to late January...but we're having some unseasonably warm weather at the moment...much of it above freezing. Heck, the temps are above 0C (32F) during the day and below freezing at night...normally this would make me thrilled...if it were late February or early March!

[DrTimPerkins]

Growth processes require a dormancy period followed by release. There is no such dormancy requirement for tapping and sap flow. Sap flow and starch-sugar conversion are stimulated by alternating freeze-thaw conditions. Sap will flow whenever there is a drop below freezing temperatures (in the wood) followed by a thaw above freezing (in the wood tissues).

[mainebackswoodssyrup]

Dr. Tim,
On a related question.........do these early runs affect sap flow in the spring if the trees are not tapped? We noticed the trees were running last week and again this week while were putting up mainline. The end of this week into next week looks prime other than shorter days of course. We may have a 3-4 week early run which is very uncommon in this area. Things will freeze up for sure before the “traditional” season. Just curious.......