The Sweet Spot for Sap: A 2025 Maple Season Tour
This past maple season, I got the chance to work at the Fundy Maple sugar shack—a mesmerizing experience. Every year, I’d heard stories of the magic of sugar harvest season. In 2025, the season was short, but sweet. Even then, I enjoyed it! This installment of NB Fieldnotes focuses on the joys and challenges of maple season – our “Fifth Season” just before the real spring.
By Samuel LeGresley, Communications Coordinator
The UNESCO-affiliated Fundy Biosphere Region, a local nonprofit in southeastern NB, recently got the opportunity to manage the sugar bush at Turtle Creek. In this protected watershed, development and recreation is restricted in order to protect the water supply for the Greater Moncton Area. 25 years ago, the city’s forest technician started tapping maples in the woods behind the reservoir. Once called Moncton Maple, it is now fittingly dubbed Fundy Maple.
Of spiles and squirrels : the history of maple sugar production
Maple sugar production is a low-impact form of managing the woods, when done right. It’s been practiced by Indigenous peoples for millennia after observing squirrels and other animals enjoying the sweet sap. Eventually, communities began using birch-bark buckets, and wooden spiles – the name of the “tap” used to get the syrup.
Today, many operations like Fundy Maple use plastic spiles. Plastic spiles are much smaller than metal, and can be connected together with pipes to help sap flow with the help of a vacuum pump.
While convenient, this setup means all sorts of things can impact the pipes – fallen trees, animals passing through, and even some creatures chewing on them to get the sweet sugar. The lines must be walked every day, and the machine turned on to get the sap. That’s when I got to visit the bush, as I was working alongside Fundy Biosphere staff running tours.
A tour of the bush
The snow had just melted last night, and there were droplets on all the branches. What a pretty sight.
The 25 kilometers of pipes could be walked in a 2-km loop, so that’s what we did.
Nigel McLaughlin, the producer at Fundy Maple, saw a line that had fallen. The cause : the spile was eroded, which caused it to eject from the tree.
What he has to do : use specialized tools to join the pipes together using fittings, and then cutting off the excess.
The old equipment from the 1950s can still be seen here, preceding the current operation by 50 years. And this sap you see here is what flowed overnight. As we left, we saw a deer look at us, probably deciding which line to chew on next.
The 2025 season and its lingering weather
All in all, compared to 2024, this year felt like a bit of a tease. The 2023 season had also been tricky, so seeing this pattern up close really drove home how much maple sugaring depends on the weather. Nigel summed it up perfectly:
“Last year was great. It was a windfall year for us. This year, not so much. It was either too warm for too long or too cold for too long, so we didn’t really get that movement of sap we were looking for. That really hindered production.”
The Science Behind Sap Flow
Working at Fundy Maple gave me a front-row seat to the sugaring process. Part of my job included leading tours, which deepened my appreciation for the science behind sap flow.
Maple sap flow in late winter is entirely dependent on temperature swings, much different than birch sap which is dependent on root pressure. I even had to brush up on the science to fully understand it!
The Freeze-Thaw Cycle and the Flow of Sugar
Sap flows in late winter and early spring thanks to a delicate balance of freezing and thawing. Here’s how it works:
- In winter, ice forms in the xylem (one of the two types of tissue that transports nutrients in the wood) fiber cells.
- Special cells (ray parenchyma cells) convert stored starch into sucrose (sugar), which gets concentrated in the xylem vessels
- When daytime temperatures rise above freezing, the ice melts, creating positive pressure inside the tree. If tapped, the pressurized sap flows out.
- When nighttime temperatures drop below freezing, negative pressure (like suction) pulls water from the soil back into the tree to replace lost sap.
For a strong sugaring season, this cycle needs to repeat consistently.
(Source)
As Nigel pointed out, that crucial back-and-forth just didn’t happen the way it should have, many days this year. If it stays warm for too long, the freeze-thaw cycle doesn’t kick in reliably. If it’s too cold for extended periods, the pressure never builds properly. Basically, the natural “pump” driving sap flow often didn’t quite get into a steady rhythm.
Maple sugaring is a labor of love, and even when the sap isn’t flowing as much as we’d like, there’s always something to do.
Looking Ahead
The modern season’s unpredictability raises big questions about the future of maple sugaring. The Fundy Biosphere region is researching resilient native species, including Sugar Maple, and studying trees that prefer southern warmth and are likely to experience a longer growing season and faster growth. The Sugar Maple is part of their Forests of the Future program, which works to establish and promote resilient forests in the region.
It also makes me wonder: If maple sugaring depends on late-winter freezes, will the season keep getting shorter or less predictable? Climate shifts might mean that the sugaring season we’ve always known is starting to change. Maple trees move very slowly north, and their range might get squeezed because of factors not only including range of maples, but also temperature.
Despite the ups and downs of this year, being part of the process was an incredible learning experience. Seeing firsthand how weather impacts maple sugaring—and how much effort goes into every drop of syrup—gave me a new appreciation for it.
Here’s hoping we’ll get to taste the sweet fruit of our labor for many years to come!
