A Technical Report from The Bartlett Tree Research Laboratories
Winter drying, winter injury, and winterkill are synonymous terms applied to a foliage disorder common on evergreens in northerly climates. Winter drying typically occurs on warm, windy days following a period of cold (subfreezing) weather. Under these conditions, moisture loss through the foliage is greatly accelerated, while replacement of the transpired water is restricted because the soil is either frozen or too cold to permit water absorption throughout the roots, desiccation and death of the foliage results. In severe instances, buds may also be affected and death of twigs and entire branches may occur.