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Report on Maple Sap Flow for 2018

at Yoder's Sugar Bush in northern Indiana

Sap runs are intimately connected to the weather. Sugaring requires that we lay aside all other personal intent and, for a season, walk in step with the natural world.


Sugaring Season, 2018


We fiinished tapping about 240 trees on Friday, February 16. The warm weather the following week brings a good flow of sap.


March conditions were outstanding. We experienced many sunny days with overnight temperatures well below freezing and daytime temperatures above freezing and rarely above 50F - perfect conditions for abundant, clear, cold sap.

By the end of the third week of March, the tapholes had begun to dry up after being open for a month, and we closed March 24.





Data for current and past temperatures at the Yoder Farm is available from the Indiana Geological Survey's station on the farm at


pouring sap Sugaring is a great time for friends and neighbors to visit and lend a hand


Current Weather Forecast for the Sugar Bush

Try your hand at predicting the sap flow |

Weather Conditions We Like to See

Sap flow is sensitively linked to weather conditions. Good flow comes with below freezing temperatures at night followed by bright sunshine and daytime temperatures well above freezing.Runs can occur with a falling barometer such as may occur before a wet March snowstorm. Flow does not occur if temperatures remain below freezing.

Flow ceases once overnight temperatures consistently remain above freezing.

In the example shown at the right, temperatures were at freezing Saturday evening, (left arrow) but there was a dramatic rise to nearly 60 degrees about 2:30 am Sunday morning. (arrow at right) This produced a voluminous sap flow that carried on into Monday and Tuesday even after the temperature decreased.

 photo -- recording thermometer at the sugarbush for 2/25/01