This is the second edition of the Vermont Maple Bulletin of 2016. If the first edition was all about warm temperatures, then this report will be about cold temperatures. The graphs below are of temperatures in Bennington (Top) and Derby (Bottom) beginning February 1st. Interestingly, the daily high temperatures reported at the beginning of the month in Derby (far northern VT) where higher than that was observed in Bennington (far southern VT). Another point of interest is that the wide swings in temperature over the last 14 days combine to make about average temperature for early February (a good example that averages don’t always tell the whole story). While temperatures are expected to moderate some early this week as well as over the weekend, sap flow will likely be limited given the very low temperatures over the last three days. Sustained warm temperatures will be needed to thaw out tapped trees and tubing systems. It does not appear as though a substantial run of sap can be expected in the coming week.
Production of syrup in operations that have collected enough sap to boil syrup appears to be limited to at most, 15-18% of a good crop. No issues of unexpected off flavors or abnormally low sap sugar content has been reported.
The operations from across Vermont who have contributed information for this project span a wide range in size, elevation and general temperature. Currently there are eight operations from six counties running the length of the state reporting information.
The picture above illustrates how one variable (such as aspect) can have a big impact on the climate in a sugarbush. The elevation of a sugarbush can also play a role in the weather a particular section of woods or a given tree experiences. Contributors to this project report tapped trees growing as low as 400 feet in elevation and as high as 2300 feet. Early warming, cold air drainage and temperature inversions have all been known to impact the flow of sap. Slush in the lines can be especially problematic in operations with tubing systems that span a large elevation range.
The unseasonably cold temperatures have halted most tapping crews trying to avoid damaging frozen stems and frostbite. Sugarmakers across the state have reported everything from just beginning tapping this week to almost fully tapped. A few operations reported being about 1/3 tapped before the cold temperatures arrived. Big operations tend to be closer to fully tapped probably given their seasonally large crew size.
The operations from across Vermont have contributed information for this project and span a wide range in size, elevation and general temperature. Currently there are eight operations from six counties running the length of the state reporting information.
Stay tuned for next weeks Bulletin.