Recognizing and preventing winter damage in your landscape

Winter can be a challenging season for your landscape, with many struggling to survive harsh conditions. From extreme cold to heavy snow, a variety of winter injuries can affect your trees and shrubs. Understanding these common types of winter injury such as desiccation, frost and freeze, bark splitting, heavy snow and ice accumulation, hardiness variations, and delayed damage can help you identify problems early and take the right steps to support your plants in the spring.

Desiccation

Desiccation, or winter burn, occurs when plant tissue loses moisture faster than the plant can absorb it during winter. This is a common injury in evergreen plants, such as conifers, because their needles remain active throughout the winter months. The combination of dry, cold winds and frozen soil prevents the roots from absorbing water, while the plant continues to lose water through transpiration. The resulting injury is dry, brown, or scorched foliage, especially on the exposed sides of the plants.

Symptoms

Browning or yellowing evergreen needles or leaves with edges appearing burnt or scorched.

Prevention

Proper winter watering before the ground freezes in the fall or early winter, applying a windbreak or mulch, and using an anti-desiccant spray to help minimize moisture loss.

Frost and Freeze Damage

Frost damage occurs when rapid freezing temperatures cause the water within the plants to freeze. As the water freezes, it expands, rupturing the cell walls and leading to irreversible damage. This often happens when temperatures begin to warm and then suddenly drop, which is common during our spring season.

Symptoms

Blackened, mushy plant tissue, particularly in the newly emerged growth. Woody plants may develop cracks or splits in the bark.

Prevention

Select frost-resistant plants and cover tender plants during cold snaps. Avoid early pruning in spring to allow plants to harden off properly.

Bark Splitting

Daytime and nighttime temperature differences during late winter and early spring (e.g., warm days followed by freezing nights) can cause the bark of trees especially thin-barked varieties like River Birch or White Oaks to expand and contract. This exposes the inner tissues to cold damage or pest infestations.

Symptoms

Vertical cracks or splits in the bark, often accompanied by exposed, damaged underlying tissue.

Prevention

The best preventive method is to plant the proper plant in the proper location. Wrapping tree trunks with burlap or tree wrap can help reduce the stress of these temperature fluctuations. Mulching at the base of the tree or shrub can help maintain a consistent temperature around the roots.

Heavy Snow and Ice Accumulation

Heavy snow or ice can stress plants, specifically their branches or stems. The weight of the snow can break limbs, flatten shrubs, or cause structural damage. Evergreens are particularly vulnerable as snow can accumulate on their branches and needles and cause them to break.

Symptoms

Broken or bent branches, flattened shrubs, or stripped limbs due to the weight of snow or ice.

Prevention

Gently brush snow or ice off from plants with a broom, especially after heavy storms. For shrubs and trees with vulnerable branches, consider tying them up with twine or staking them in advance.

Hardiness Variation

Plant Hardiness refers to a plant’s ability to withstand cold temperatures. If a plant is not suited to the local climate or is planted too late and not allowed to fully acclimate, it may suffer from cold stress. Newly planted trees and shrubs may also be more vulnerable to winter injury.

Symptoms

Wilting, browning, or dieback of the plant will occur if the plant is not adapted to the cold temperatures in the area.

Prevention

Always choose plants that are appropriate for your USDA Hardiness Zone. For newly planted specimens, extra care in the first few years such as fall watering (until the ground freezes), mulching, and protection from extreme temperatures can help them survive cold temperatures. Planting new plantings early in the growing season also aids in their establishment, allowing them to better withstand the winter months.

Delayed Damage

Some winter damage is not visible until later in the growing season. In certain cases, frost or freeze injury may affect plant tissue deep inside, with symptoms appearing only after plants start to grow in spring. This delayed damage can prevent plants from leafing out or cause them to grow poorly.

Symptoms

Delayed leaf drop, stunted growth, or overall failure to thrive during the growing season. In severe cases, plants may not leaf out at all in the spring.

Prevention

Careful monitoring during the winter can help identify potential damage early. However, once the symptoms appear, there is little that can be done to reverse severe damage. The key is prevention by protecting tender plants before extreme temperatures.

Conclusion

Winter can be tough on plants, but with a little extra care and attention, you can minimize damage and ensure a healthy landscape come spring. Learning to recognize the signs of winter injury and taking preventative measures in the fall will set up your trees and shrubs for success. Regularly monitoring your plants throughout the cold months can help prepare them for the challenges that come with winter.

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