The Problem

For recently planted or potted evergreen seedlings, additional care through the winter season is suggested to provide your new evergreen with the best chances of survival.  A common affliction of new evergreens during winter is to suffer from winterburn.  Unlike deciduous trees, evergreen trees do not enter a full state of dormancy.  This also means that their process of photosynthesis continues throughout the winter.  This process, which involves the absorption of light through the trees needles requires the tree’s root system to provide the necessary water to keep the needles moist.  During winter, a frozen ground will substantially limit the seedlings’ ability to extract the necessary water from the ground.  During winter periods of extreme cold (frozen ground) or extreme mild (warm full sun) the new seedling will be most susceptible to winterburn.

Impact to Tree

The extent of damage caused to Evergreens can vary dramatically depending on the severity of exposure to extreme elements.  In general, the impact can range from total loss of tree, whole branches or sections dying off, or yellowing/browning of needles. Damaged sections may become noticeable in late winter through the early spring.  While damaged or brown sections will not return to a green color, it is recommended to restrict any pruning until new growth appears.  In some cases, damaged or dead areas may be hidden by new growth eliminating the need for pruning back branches.

How to Protect and Avoid

Evergreen trees planted in the spring having gone through one season’s growth cycle will be less susceptible to winterburn than fall planted Evergreens due to better established roots.  Regardless, in the right conditions of wind, cold, and/or sun any new evergreen is at risk. 

Overwintering in Root Pouch

If purchased in the fall and waiting for spring to plant, it is highly recommended to place your potted evergreen in a secure area that limits the amount of sunlight and wind exposure.  Next to a house, garage, or porch is often a good location to help protect from the elements.  When possible, placing the root pouch in a bed of mulch may help provide extra protection from wind.  During extended periods of no rain, it may be necessary to provide supplemental water to your potted tree (during above freezing temps).

Planted Tree’s First Winter

For spring planted evergreens, it is unlikely that total tree loss would occur from winterburn.  More likely is an unprotected tree will lose some needles/branches.  Fall planted trees are much more likely to suffer total loss and steps to avoid winterburn should be considered for the health of the tree.  winterburn can be reduced or avoided by providing the evergreen with full shade during the winter.  A 5-gallon bucket (properly secured down) placed over top the tree with holes drilled for aeration is an excellent solution for about $5.  Commercially made products for protecting newly planted trees over winter can also be purchased online to the size required.

Regardless of when you are planting or the methods you take to protect your evergreen, the main goal is to limit or avoid as much exposure to 1) high amount sun during below freezing temperatures 2) high amounts of wind.  Any measures taken to help mitigate these two items will go along way to ensuring the health and survival of your new evergreen.