Tree roots effectively wedge apart rocks and cause material to be broken into smaller pieces. As the roots continue to grow, spaces will continue to widen. The spaces will often fill with water. The composition of the constituent minerals is changed by chemical decomposition. Even some of the individual mineral grains have cleavage planes or minute cracks which admit some moisture. During seasons when repeated freezing and thawing occurs, the process of frost wedging will accelerate the breakdown of rock.

With support from the Center for Applied Technologies in Education, The Earth Science Digital Library is an initiative authored by Russell Agostaro, Newburgh Enlarged City School District, Newburgh, New York.