How Does a Tree Make Sap?
Sap is the liquid that flows through trees and other plants and helps them live and grow. The roots of a tree draw from the soil a combination of water and dissolved minerals. This liquid sap flows through tiny tubes in the trunk and branches, up to the leaves.
Through a process called “photosynthesis,” the green chlorophyll in the leaves combines the liquid with sunlight and air to make food for the tree. The sap is now fortified with plant food made by the leaves, and minerals acquired from the soil.
As the sap flows through the tree it feeds every living cell. Tree sap flows through sapwood, which produces carbon dioxide. Sometimes this carbon dioxide causes pressure to build up within the tree. If there are any wounds or openings, this pressure will eventually force the tree sap to ooze from the tree.
Oozing tree sap can also be heat related. In early spring, while many trees are still dormant, the fluctuation of temperatures may affect the flow of tree sap. For instance, warmer weather produces pressure within the tree. This pressure can sometimes cause the tree sap to flow from the tree through openings produced from cracks or injury.
During cold weather, when temperatures fall below freezing, the tree pulls water up through the roots, replenishing the tree sap. This cycle is continues until the weather stabilizes and is quite normal.
Many people are startled by the sight of sap on their tree. They may wonder what is tree sap and what does tree sap contain? Xylem sap consists primarily of water, along with hormones, minerals, and nutrients. Phloem sap consists primarily of water, in addition to sugar, hormones, and mineral elements dissolved within it.