Winter damage can occur on many plants. A rapid temperature drop following a mid-winter thaw can cause bark splitting. Dead twigs and branches in the spring may be the result of ice and snow damage from the winter.
Ice and snow damage
- Symptoms include bent or broken branches from the heavyweight of the ice or snow.
- Heavy snow can be gently knocked from branches, but branches that are iced over may actually be more brittle and suffer further damage if removal is attempted.
- Wind during ice storms will cause the most damage.
- White pines in our area are especially prone to winter ice and wind damage.
Winter color of evergreens
Winter damage symptoms on boxwood
- Symptoms of winter color can include gray, yellow, blue, purple, bluish-green, brown, and bronze leaves or needles.
- Examples include
1) Japanese cedar (Cryptomeria) turn bronze
2) Yew (Taxus buccata) turn brown
3) Eastern red cedar (Juniperus virginiana) turn brown
4) Arborvitae turn brown
5) Creeping juniper (Juniperus horizontalis) turn purple
6) White pines (Pinus strobus) turn yellow
7) Boxwood turn yellow-orange
- Examples include
- Some evergreens such as Leyland cypress and spruce usually don’t change color, but dieback in Leyland cypresses can occur under extreme winter temperature fluctuations.
Severe winter damage on Leyland cypress. Photo: David L. Clement
- Causes of ‘winter color’ can include low temperatures and drought stress. Often, the foliage colors will revert back to normal when springtime temperatures return to normal.
- Cultural practices that conserve soil moisture, prevent root damage, and promote “hardening off” prior to winter will reduce winter damage.
- Avoid fertilization or pruning in late summer, which stimulates late season growth that does not have time to “harden off” properly and is much more susceptible to winter injury.
- When watering in the fall, soak the soil several inches deep, and then allow it to dry between waterings. This encourages deeper rooting. Avoid frequent shallow sprinklings, which encourage surface roots that are easily injured by drought and cold.
- Freshwater sprays on foliage and deep watering in early spring will also help wash deicing salts from the leaves or needles and flush salts through the root zone faster to help reduce desiccation damage.
- The use of mulches conserves soil moisture and prevents temperature fluctuations. Mulches also keep the soil cold in early spring, which helps to reduce premature bud break.
- Wait until the plant puts out new growth in the spring and assess the damage.
- Typically, damaged leaves fall off or are masked by new growth. Severely damaged shrubs may benefit from pruning. Prune to remove dead, damaged or broken branches and to stimulate new growth.