This winter, like many, has taken a toll on evergreens in our gardens and landscapes. Just driving down the highway or through a neighborhood, you can notice browning on evergreen shrubs and trees. So the question is, why does this happen?
Since evergreens retain their leaves throughout the winter, they are susceptible to a variety of winter related problems. These leaves are still living and need to be able to use and uptake water from the soil.
A good portion of the browning that we see on evergreens is caused by winter burn or dessication. This happens when cold winter winds blow past evergreens and pull moisture out of the leaves at a more rapid rate than the plant can replace the moisture. If the ground is frozen and the plant cannot uptake enough water, the leaves then brown as a result. This typically shows up on the windward, sun-exposed side of the plant and is not uniformly spaced around the plant. This can happen on young, as well as old trees and shrubs.
The other possible cause of browning on evergreens could be from salt spray. This browning can occur on evergreens that are close to sidewalks and roadways where de-icing salt may have been splashed on the plant. Since salt draws water from plant tissue, this salt spray can cause winter burn in evergreens. This again will appear on only the side of the tree closest to the sidewalk or street.
Luckily, many times an evergreen come overcome this damage if it just occurs on a portion of the plant. One way to verify if your plant is still viable and living, is to check and see if the branches and buds are still alive. Scratch the bark of a young branch that has browning and check to see if the inside is green and living, or if it is brown and dried out. If the branch is still green and living, there is a good chance that the branch will continue to grow and overcome that needle loss. Just give it some time. It will take some time for the evergreen drop those dead needles and fill back in.
If this browning occurred in other times of the year, or if the pattern is more uniform and not confined to one side of an evergreen, this could be a sign of other issues. Various diseases are known to cause problems with evergreen trees and shrubs. Drought conditions and improper water procedures have also caused many evergreen problems in recent years.
If you suspect other problems, our Master Gardener Hotlines will be starting this spring in each of our local Extension offices. They are a great resource to help you identify and solve your plant problems. Contact your local Extension office through our webpage. You can also post questions on our Facebook page.
To prevent this problem next year, make sure evergreens are well watered in the fall going into winter. Anti-dessicant sprays can also be purchased and applied following the label's directions next season and a burlap wrap around the plant can also deflect some wind.