Winter Injury to Evergreen

Just like other trees, evergreens suffer damages during winter. Some of the most susceptible evergreens include Yew, hemlock, and arborvitae. However, all evergreens can suffer from winter browning. Some of the most sensitive evergreens include the new transplants. Also prone to damage are plants with succulent late-season grown. Some of the common forms of winter damage in evergreens include:

Several factors may lead to discoloration of evergreen foliage during winter. Winter sun and excessive wind lead to excessive loss of water in evergreen foliage. Freezing of the roots in the soil prevents them from absorbing and replacing lost water. The loss of water leads to drying out or desiccation of the plant tissue leading to browning. The foliage may also suffer damage due to abrupt temperatures fluctuations. The foliage warms up during the bright sunny winter days and this helps to initiate cellular activity. However, when the sun sets or if clouds block the sun, foliage temperature drops and this may injure or even kill the foliage.

It is common to experience bright yet cold winter days. These days harm the foliage because they destroy the chlorophyll in the foliage. It is impossible for chlorophyll to re- synthesize when temperatures are below 28 degrees. Therefore, bright cold winter days lead to bleaching of the foliage. When cold temperatures occur early in the fall before plants have hardened off completely, it may lead to injury or death of non-acclimated tissue. Similar damage may occur if cold temperatures occur in late spring after new growth has occurred.

In most cases, leaf damage does not affect the whole plant. In most cases, leaf damage occurs on the windward sides of the plant. The leaf damage only occurs in the whole plant in extreme winter conditions.