What keeps trees from freezing in winter?

Sap is in tree wood. It is collected in the spring.

Sap is in the xylem (tubes in the wood of trees that allow water to flow) of trees. It is collected in spring. People tap into the wood of a tree. The sap drips out. It is collected in a bucket. Then, it is cooked to make maple syrup.

Photo Credit: Marc Bruxelle RF/Alamy Stock Photo