What Is Winter Burn and How Do You Treat It?
Winter burn is a common problem in many evergreen shrubs, brought on by dry conditions and a lack of moisture. More specifically, it is caused by desiccation brought on by freezing temperatures and cold winter winds stripping water from the shrubs’ leaves. The most common symptoms are yellowing, bronzing, or browning of the foliage.
How does Winter Burn Happen?
Plants continuously lose water to the atmosphere through openings in their leaves in a process called transpiration. Usually, this water is replenished from the soil. However, in the winter, roots can’t pull moisture from the frozen ground. When transpiration is coupled with harsh winter winds removing additional water from the plant, the leaves dry out and die.
How to Treat Winter Burn
Unfortunately, there is no way to treat or repair the damage once winter burn occurs. When severe enough, it can kill the entire shrub. Because of this, prevention is critical.
How to Prevent Winter Burn
For a long time, it was recommended to wrap evergreen shrubs in burlap for the winter to protect them from winter burn. More recent research has shown there are much better ways to protect the plants from harsh, dry winter conditions.
Prevention also includes caring for your plants properly through the growing season.
- Plant the best shrubs for your hardiness zone. Some varieties are more cold tolerant than others, offering natural protection.
- Continue to water shrubs well through the fall and into the winter until the ground freezes.
- Layer a few inches of mulch around the base of your shrubs to help insulate the soil and increase the moisture it holds. Make sure to spread the mulch out a few feet from the stem to protect the root system since they spread through the soil as they grow.
- In the late fall, apply a slow-release fertilizer to your shrubs to help encourage root growth before winter.
- In areas prone to high winds, create windbreaks using plastic or burlap about 18-inches from the shrub on the windward side.
- Ensure good soil drainage during the growing season to prevent root rot or fungal problems. Stressed plants are more susceptible to winter burn.
- Spray your shrubs in the early fall with an anti-desiccant product. It helps retain moisture in the leaves, so you’ll see less damage when spring rolls around.