The purpose of this assessment probe is to elicit students’ ideas about weathering. The probe is designed to find out whether students recognize that plants, including small plants, can cause weathering of rock. Plant roots as they grow larger can cause rock to crack and even break apart through mechanical weathering. This probe is best used with grades 3–5, and can be combined with the four corners formative assessment classroom technique. A materials list, teacher background information, references, assessment, and outcomes are provided. This book selection includes the Table of Contents, Foreword, Preface, Acknowledgments, About the Authors, Introduction, and Index.