Protecting Evergreens for Winter
By Kerry Ann Mendez
Maine winters can be tough on evergreens, especially on younger or newly installed plants that have not developed mature root systems. Winter sun and wind can dessicate evergreens, resulting in browning foliage. Plants sited on a southern or western exposure are particularly stressed by sun scorch, as are those in the path of drying winds. The excessive water lost through foliage cannot be replaced by hydration through roots due to the frozen soil.
Below are some protective steps to help your evergreens look their best come spring.
- Water plants well in late fall before the ground freezes.
- Spread a 3-4" layer of mulch around the base of the evergreen, being careful not to build up the mulch against the trunk.
- Apply an anti-dessicant, like WILT-PRUF, on the upper and lower surfaces of the foliage in early December. The active ingredient in WILT-PRUF is a natural pine oil emulsion that is non-hazardous and organic. The oil provides a protective coating that helps plants retain moisture. Spray when the temperature is between 40 and 50 degrees and no rain or snow is expected within 24 hours. A second application can be done in mid-February when temperatures are above 40 degrees.
Note: Do not apply anti-dessicant earlier in fall! The evergreen needs to be dormant, having slowed its growth and redirected water from foliage to roots. If the anti-dessicant is sprayed too soon in the season, water is trapped within the foliage, leading to rupturing leaf cells caused by dropping temperatures resulting in browning.
- An alternative to an anti-dessicant in sunny or windy areas is to wrap the evergreen in burlap, leaving an opening at the top. You could also create a windscreen in front of the shrub with stakes and burlap.
- Be careful not to use rock salt near evergreens (or any plants). Safer options are products containing calcium, potassium or magnesium chloride.