Winter Burn is a common problem in many evergreen trees and bushes. Typically, it is a minor issue that is easily prevented but this winter's rough conditions, snowfall and record cold is going to make winter burn damage more prevalent, and more severe this spring.
What is Winter Burn in Evergreens?
Winter Burn is the yellowing of branches and foliage on non-deciduous trees and shrubs such as Arborvitae, Boxwood and Spruce. Broadleaf evergreens such as Rhododendrons, Azaleas and Holly are also considered very susceptible to winter burn.
What causes Winter Burn? Simply put, exposure to harsh winter elements and a lack of moisture. The severe cold we experienced this year caused soil to freeze deeper than most years. Any moisture locked above this year's frost line also froze, cutting off the roots access to water throughout the winter. Because newly transplanted evergreens have shallower roots, many of them may have struggled to get water this year. Although we did have ample water in the soil this fall, both newly planted and established plants, had to go longer than usual without access to moisture, since the season of the deep freeze was so long. The damage can range from the needles being completely brown to just slightly brown on the tips. If your evergreen, yew or arborvitae is completely brown, it may not be dead, but suffering from correctable winter burn. Don't give up!
The winter burn will be more severe on the south and west side of the plant, caused from freezing temps, lack of soil moisture, sun and wind. This year we have had ample soil moisture but the ground was frozen so long that the evergreen roots could not take up moisture fast enough to replace what it was losing due to the wind and sun on needles or leaves. A poor assumption is that a sunny location will warm and protect the plants. In fact, a sunny location may increase damage as the sun sucked moisture out the plant more quickly than it could be replaced. Salt damage is another cause of winter burn that can be avoided by following the suggestions below.
"Are my Evergreens, Yews, and Boxwood dead?" That is a question we are already hearing. For the most part, the answer is no. A couple good rains and 60 degree days and you should start to see green coming back. The most severely damaged areas may drop some needles but the buds will be fine to sprout new growth. If it looks dead, hang in there! Do not dig up the plant. Wait it out, keep it watered and see if green starts to appear. Many yews will look completely dead and are not, just have a little patience and they should bounce back nicely. A spring application of Espoma HollyTone will help encourage new, green growth. Espoma Holly-Tone is a natural fertilizer that will increase plant vigor and encourage new growth. Do not cut off brown branches until new growth starts to flush out.
If you have concerns, our Horticulturalists can help. Feel free to bring in pictures of your plants into our garden center and our staff will be able to determine if they will bounce back. We recommend waiting until at least mid-May to make any decisions on the health of the plant in question.
How to prevent winter burn next season? We have a couple suggestions:
1. Water evergreens well into fall, until the ground freezes. Providing a little extra moisture will help reduce damage.
2. Position plants that suffer most from winter burn in shady, protected locations.
3. Cover or wrap evergreens prior to freezing temps.
4. Apply an anti-desiccant, such as Wilt-Pruf or Wilt-Stop each fall.
5. Sprinkle the soil with gypsum to release the salt from your soil.
Questions? As usual, we welcome your questions! Visit our garden center this spring in Cary, IL at the corner of Rt 31 and Rakow Road.