Winter is a strenuous time for urban evergreen plants. Evergreen plants still require water in the winter. Winter desiccation occurs when inadequate water is available in the root zone to meet the demands of leaf transpiration. When the roots are unable to provide adequate water to the leaves, cells begin to die from the tip down. This effect is pronounced during periods of strong wind or intense sunlight. Damage is typically worse on south and southwest sides of plants, or the direction facing the prevailing winds. Damage is typically worse on newly planted trees with underdeveloped root systems.
Continue watering evergreen plants as long as the ground is not frozen. Watering in late fall and early winter can supply the roots with water required for transpiration by the leaves. Newly planted trees with limited root zones need to be watered frequently until roots adequately establish.