The season is now underway statewide. It appears that the south-north temperature gradient that is more typical has reestablished itself. There was as much as a 20 degree temperature difference between the ends of the state this past weekend. The graphs below show observed temperatures in Bennington (top graph) and Derby (bottom graph).
Bennington County saw some sap flow last Monday (15th) as well as runs on Sat-Sun (20-21st). A ‘surprise’ run on Monday also yielded some sap for producers. Sap sugar content was 2.1 and grade dark with no off flavors was made by one producer.
The word from Lamoille County (as of Saturday 20th) is that although many producers were fully tapped or nearly so, only the largest producers in Lamoille County had made any syrup to speak of.
A Starksboro producer (Addison County) with a sugarbush between 1600-2000 feet in elevation (average to cold temperatures) and just over 3000 taps, finished tapping on the 17th and collected a small amount of sap on the 21st.
In central Vermont the story is similar, almost fully tapped, ready to turn the vacuum pumps on and start collecting sap (likely the 24th).
One large (80,000 taps) Franklin County producer reports good production from low elevation trees but not much from higher elevations. To date they have made 5,000 gallons of good flavored Amber and Dark syrup. Sap sugar content has been good, around 2.0 brix.
The report from Orleans County has some producers just beginning to tap. A lack of deep snow has made tapping easy compared to other years. As of Monday, no sap was flowing at an operation in Morgan considered cold (1200-1800 feet elevation).
A producer in Cannan (Essex County) reports the first run of sap came on February 2nd when temperatures were between 40-44. The sap sugar content was 1.6. Another run on 2/15 was perhaps not as strong as the earlier one and also had 1.6 for sweetness. A third run over the weekend (20th) was minor in volume but the sugar content had risen to 2.0%. Syrup has been Dark and Very Dark.
Looking forward, it appears that temperatures will conducive for sap flow through Thursday night. After that, it looks like the best chance for a run will be Sunday in areas to the south or with relatively warm sugarbushes.
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.
Introducing the University of Vermont Extension, Vermont Maple Bulletin. This will be a weekly recap of the sap flow and syrup production across the state of Vermont as well as a look ahead at the week to come. The Bulletin is meant not an exhaustive analysis or planning tool but rather a general summary of the maple season across the state. Hopefully, the information will help identify broad trends as the season progresses. Issues such as unusual sap sugar content or abundance of sugar sand or incidences of metabolism will also be included when appropriate.
To date, the winter of 2015-16 in Vermont could best be defined by its mild temperatures and lack of significant snowfall. These qualities have made repairing damage or installing new tubing much easier for producers. Tapping is also reported to be going smoothly compared to years with deep snow. Unseasonably warm temperatures have allowed for sap collection across the entire state. In most years, producers in the southern portion of the state begin producing syrup before their northern counterparts. That geographic arrangement seems much less defined in 2016.
Producers statewide appear to fall into two broad categories when it comes to starting the 2016 season: “Get while the getting is good” and “wait and see”. Producers that have enough of their woods tapped to collect significant sap report sap sweetness to be about as expected (ranging from 1.4-1.9) in most cases. Good flavored syrup has been produced with color ranging from Golden to Dark. The wide range in color is most likely due to variations in microclimate and sap collection/storage practices between operations. One large producer in northwestern Vermont reports reaching nearly 10% of a crop after only three boils. Another large producer is closer to 15% of a good crop as of Friday.
Those producers who have taken a “wait and see” approach are banking on more typical February weather (cold) returning for the next week or two. One producer reports trying to avoid collecting only enough sap to sweeten the evaporator and then shut down for an extended period. The largest reported reason for waiting is a desire to prevent reduced production in the middle to late part of the season as a result of older tapholes beginning to clog with the growth of microorganisms.
Looking ahead for next week it appears that the warm temperatures that allowed widespread early sap flow will disappear. Producers in the south expect temperatures to remain above historical averages with the possibility sap flow depending on location. In general temperatures for expected to go above freezing but remain below those needed for good flow. The northern part of the state has a similar forecast with perhaps less of a change for even modest sap flow.