Classic Wisconsin treat faces warming threat

Frank Vaisvilas

Milwaukee Journal Sentinel USA TODAY NETWORK – WISCONSIN

Longer growing season would limit maple syrup

One of Charles James’ favorite childhood memories is making syrup in the spring from the dozens of maple trees in his parents’ backyard on the Menominee Reservation in northwest Wisconsin.

Of the tribe’s 235,000 acres, about 95% are heavily forested. And of the 1 billion or so trees on the reservation, about 23% are sugar maples, ideal for tapping to make maple syrup and sugar.

James remembers other tribal families would have sugar camps in late winter and early spring, banding together to divide the labor-intensive process of turning sap into syrup and then sugar.

Those families are among thousands of maple syrup producers across Wisconsin. They range from hobbyists to commercial enterprises.

However, as much as real maple syrup has become a staple of Wisconsin culture, there is concern that climate change could bring it to an end in a generation, at least in the southern part of the state.

Temperatures have warmed up enough that scientists contend March has become part of spring instead of winter.

With the warmer temperatures, the maple sap collecting season is shifting ever earlier in the year, according to University of Wisconsin-Madison researchers.

With the growing season starting earlier and lasting longer, maple trees will grow taller. The more they grow, the more they will need to consume their own sugar, leaving less sap to be tapped for syrup. That will lead to more variability in annual production.

In a few decades, along what is now the southern edge of the current sugar maple range, tapping will likely become impractical, the researchers suggest.

“The climate has been a factor through the years,” said Theresa Baroun, director of the Wisconsin Maple Syrup Producers Association. “‘May’ is the keyword. We don’t know what will happen in 30 years.”

Tribal member came back to his tradition

The Indigenous peoples of Turtle Island (North America) taught the first European colonizers how to tap maple trees to make maple sugar or syrup, according to historians. James had gotten away from maple tapping and other harvesting in the Menominee Forest as he grew older. But he recently started tapping again in earnest now that he has his own family. He wanted to pass down the tradition to his three boys, ages 4, 10 and 17 and, now, an infant daughter.

When James was young, tribal elders would explain the Menominee method of harvesting maple sap. First, give

Menominee tribal member Charles James uses a traditional process of making maple sugar on March 24 in Keshena.

PHOTOS BY JOVANNY HERNANDEZ/MILWAUKEE JOURNAL SENTINEL

Menominee tribal member Carol James carries jars of homemade maple syrup on March 24 in Keshena.

thanks to the tree relative and Creator, because as the winter dragged on, manoomin (wild rice) and other food had become scarce.

Then, after making sure the tree was big enough, tap a spigot 1 1 / 2 to 2 inches deep and attach a bucket or bag to collect the sap.

Forty gallons of sap boils down to one gallon of syrup.

“They love to taste the syrup to make sure it’s sweet enough,” James said of his sons.

His wife, Carol, has expanded the operation to make cakes, suckers and other sweets from the maple sap to give out to relatives and friends.

Northern Wisconsin should be less vulnerable

Four types of maple trees can be tapped for their sap to make syrup: sugar, silver, red and black. But black maple is much less prevalent in Wisconsin, and sugar maple produces the highest sugar content.

In Wisconsin, there are more than 2.2 billion maple trees that are at least 4 1 / 2

feet tall, according to the Department of Natural Resources. More than 863 million are sugar maples.

Wisconsin’s maple syrup production in 2025 was 556,000 gallons, up 98,000 gallons from 2024, Baroun said. That lifted the state to the third largest producer in the United States, behind Vermont and New York. It had been fourth, but passed Maine.

If tapping maple trees along the southern range fades, harvesters can look toward other trees, such as black walnut and birch. Black walnut syrup is described as nutty or butterscotch flavored, and the tapping process is similar to that of sugar maples.

As for the northern part of the state, climate change is also affecting the tapping season.

James said he remembers not too long ago it wouldn’t start until mid-March. Now, it can start in early February and wrap up by the end of March.

But the harvest does not appear vulnerable. And for people like James, that means the traditions can carry on.

“Every time I step out in the woods I take a breath,” James said. “When you’re younger you don’t understand what you have. ... It makes you feel rich, not in a money kind of way. It makes your soul feel rich.”

Menominee tribal member Charles James unloads a bag of sap from a maple tree in the Menominee Forest on March 24 in Keshena.

JOVANNY HERNANDEZ / MILWAUKEE JOURNAL SENTINEL