Duration of sub lethal temperatures is also a factor. Canadian research has shown that at 5 degrees F the ability of plants to survive declines after 12 hours of exposure. At 0 degrees F survival rates drop after only one hour. Snow cover and soil moisture play significant roles in cold injury. Experience indicates that even a light snow cover, especially in deep furrow plantings, can prevent serious damage.
Cold injury is also a dehydration process.
Water freezes in intercellular spaces which leads to water loss from cells and water movement in the plant. If a plant is under water stress, injury may occur due to desiccation - freeze drying essentially. High moisture content can also lead to injury. High water content in the crown can lead to dilution of natural antifreeze materials and thus make these materials less effective. For those plants that are still alive, a disease, Cephalosporium stripe may take the field.