GOSHEN, Ind. — Maple syrup could be in short supply in Indiana and other parts of the Midwest this year. The flow of sap now that temperatures are fluctuating should be reaching its peak – but throughout northern Indiana and Michigan it remains at a trickle.

Many producers speculate the near-record cold February has something to do with it, but the actual cause and whether flows will pick up before the annual sap run ends has them merely guessing.

“Maple syrup makers are just scratching their heads,” said Larry Yoder of Goshen.

Yoder, whose family has tapped maple trees for more than a century, estimated the amount of sap his 225 trees have given is down 80 percent and, if things don’t pick up, his output will be the lowest he can ever recall. Yoder, who is in his seventies, said he started tapping trees as a child.

“The sap is there but not in the quantity and volume that producers are used to,” he explained.

The sap was also 2-3 weeks late flowing with taps usually in the trees by no later than mid- to late February. Yoder said it wasn’t until the first weekend in March when all of his trees were tapped.

The bitter cold February and extended cold temperatures are blamed for the late start of sap flowing because of the warmth needed for maple trees to thaw and start producing. Leslie Witkowski, interpretive services manager for St. Joseph County Parks, said sap production is also down significantly at Bendix Woods County Park near New Carlisle where the annual Sugar Camp Days was recently.

Normally, enough maple syrup is derived from the sap in the trees at Bendix Woods to sell and use as ingredients for food during the weekend festival. Other sources of maple syrup had to be brought in, though, to make such treats as maple candy, maple cotton candy and maple hot dogs.

“It’s been not the most cooperative season to start off with,” said Witkowski, who noted the sap that is being produced is high-quality with normal sugar content.

Fluctuations in temperature above freezing during the day and below freezing at night causes maple trees to expand and contract, generating the pressure inside the tree necessary to force the sap out of taps. Yoder said the late sap run was expected, from the frost being so deep in the ground keeping the roots too cold to trigger the sap-making process on time.

However, with the roots warming up from frost leaving the ground, sap flows are still nowhere near where they should be, even with temperatures fluctuating more above and below freezing during a 24-hour period. Flows are not much greater even in the trees fastened to lines hooked up to vacuums to draw out more of the sap.

“That just isn’t happening this year,” added Yoder.

Another concern is that the window for sap production is narrowing because once temperatures stay above freezing the trees no longer expand and contract, shutting off the flow. And in some areas. temperatures have remained above freezing on some days, contributing to the problem.

It takes about 40 gallons of sap boiled down to make one gallon of maple syrup. Yoder said he usually makes 50-80 gallons of maple syrup during the season, but right now he’s on a pace to come away with much less. “I’ll be happy with 10 gallons if this weather pattern and sap flow continues,” he said.

Self-proclaimed sugar makers in other states such as Michigan and Ohio also report considerably lower outputs this year – even those who’ve tapped more trees. Mike Grace, a naturalist at De Graff Nature Center in Holland, Mich., said just three gallons of syrup have been made so far at his site, when 30-35 gallons is typical during their season.

“Maybe the frost is taking longer to get out of the ground. That’s one of our hypotheses, anyway,” said Grace, who speculated low sap production might have something to do with an usually large amount of maple tree seedlings taking root last year.

After the brutal winter, he said the sap run was late in starting but once the ground warmed up normal sap production resumed, creating more confusion over the outputs this year. “It’s a little strange,” he noted.

Jen Freeman, vice president of Richards Maple Products near Cleveland, Ohio, said it is the latest sap run at her 500 tapped trees operation in at least 30 years. Her trees did put out 1,100 gallons of sap over a four-day period – an amount she felt could have been better but still was decent.

Even if the weather begins to cooperate more, she expects the average six-week season to be two weeks shorter, with longer hours to collect and boil down as much sap as possible because of the late start. “It seems to be a very late and very slow start,” she added.

Low output means sugar makers taking a financial hit and, perhaps, failure to meet a growing demand for organic or all-natural foods like maple syrup. Yoder, for example, sells his 8-ounce bottles of maple syrup at $5 at festivals and farmers’ markets, so he could be staring at a loss of as much as $4,000.

“The restricted production is going to mean maple producers are not going to see the income they normally would,” he said.