Technical Abstract: One aspect of winterhardiness in small grains that has received little attention is the period of recovery following freezing when repair mechanisms could significantly impact how or if a plant survives freezing. In this study rye, wheat, barley and oat were frozen and their crowns histologically studied during a 2 week recovery period after freezing. Oat had a unique response to freezing consisting of a barrier that stained deep red and separated live from dead tissue within the crown. We used vital stains, color recognition, fluorescence microscopy and 3D reconstruction to characterize this barrier in preparation for a study of the change in metabolism of the crown during freezing. These observations will help scientists better understand the ability of crops to adapt to climate change. 3D reconstruction techniques used here to study recovery from freezing can be used in a variety of scientific endeavors including effect(s) of pathogens on crops and even structural analysis of animal organs in mammalian tissues.