Every year I teach several winter-tree identification classes. Even though they are always held outdoors no matter how cold it is, student evaluations indicate such classes are generally fun. Showing ...

Add Yahoo as a preferred source to see more of our stories on Google. Getty Images Unless you are intent on making your own maple syrup, you probably haven't given tree sap much thought. So, let's ...

Just as blood moves important stuff around the human body, sugary sap moves important things around a tree. My friend Nadia Valverdi told me all about it. She’s a researcher at Washington State ...

Unless you are intent on making your own maple syrup, you probably haven't given tree sap much thought. So, let's take a deeper dive into a tree's 'blood' or sap and the normal flow in the fall for ...