Winter burn on evergreens is damage to the leaves caused by cold winds. The winds dries out the leaves and that cause the damage. There are anti-transpirants or anti-desiccants that can be applied to the leaves that help reduce this type of damage. When leaves give off water into the atmosphere it is known as transpiration. As the water transpires from the leaves it is replaced by water coming up from the roots. When the ground is frozen the plant can not take up water because it is frozen also. Exposed to the wind too long your evergreen leaves will brown and die.
These chemicals can help slow down transpiration when applied properly. The leaf is coated and protected by the anti-desiccant. In general broad leaf evergreens are more susceptible to burn than needle evergreens because of the size of the exposed leaf area.
There are several things that you can do to help to minimize leaf burn. First if you have had a dry fall and there is not a lot of moisture in the ground because of a lack of rainfall, you need to water your evergreens thoroughly. Get buckets of water and slowly water around the base of your plants let the water soak in and then apply some more.The best thing is if you can do this a couple of times before the ground freezes. I know that this may seem a bit of work but it will help keep the damage down. You can also put up a mind barrier around the lower growing evergreens. Place sturdy stakes into the ground and stretch burlap across on the side of the prevailing winds this will help also by cutting down on that cold wind.
In late December and then again towards the end of January apply anti-desiccants to the leaves of the evergreens. This must be done when the weather is above freezing however for 24 hours. This may be difficult during January but hope for a January thaw. Make sure you follow the label directions.
Here is a list of evergreen plant material that can sustain winter leaf burn.
Other evergreens that may suffer leaf burn include
The conifers such as Pines, Spruces, and Cedars are also susceptible , especially if they have been planted as a wind break. Again for these larger evergreens try to water them well and apply the anti-desiccant. Usually your pants will recover from winter leaf burn but severe damage can weaken the plants and cause an early demise.