Friends of the Forest Preserves

During the transition from winter to spring, some types of trees begin to produce large amounts of tree sap. Trees, like sugar maples, don’t do this just so humans can make syrup though. This sugary liquid is meant to give trees the energy they need to produce their first flowers and leaves of the year. In the winter, trees start to convert starches stored inside their bark into sugar. Once daytime temperatures warm enough to melt frozen water inside of trees, these sugars become dissolved in water. For most of the year, this sugary sap flows slowly throughout the tree, providing energy for growth. But during this time of year, the sap becomes pressurized by cycles of warm days and freezing nights allowing it to drip out of wounds in the bark, or a maple syrup tap. Because of these requirements, sap only flows for around one month out of the year.