Cold nights and warm, sunny days increase the amount of the sap flow in a Maple Sugar tree, making weather an important factor in the quality of a sugaring season. But it’s not the only factor. Both the amount of sap flowing as well as its sugar content affect a given season’s maple syrup production.
Recent research indicates that the size of a tree’s seed crop in the fall is a good predictor of the sugar content of its sap the following spring. A tree, through photosynthesis, produces and stores a given amount of carbohydrates. These carbohydrates are utilized in the production of seeds as well as the production of sugar. Once the carbohydrates are used up, over a year is needed for the tree to replace them. If a lot of seeds are produced in the fall, there are fewer carbohydrates available for the production of sugar the following spring. Hence, while the weather in a given spring may be conducive for the ample flow of sap, the sap that flows may have a very low sugar content if a tree produced a lot of seeds the previous fall, making it necessary to boil more sap to achieve the desired sugar content in the maple syrup. (Source: Northern Woodlands magazine)