Winter Damage
What winter damage is, and what to do right now to prevent it
Winter Damaged Rhododendron
Now that winter seems to be really here, it’s a good time to address the most common cause of winter damage to shrubs: wind and sun. Did you think it was cold and snow? A lot of people do, but that is a misconception. In fact snow acts as an insulator and protects plants. The real damage happens when winter wind and sun draw moisture out of plants and, because the ground is frozen, the plant’s roots cannot replace the lost moisture. Common examples of winter damage are browning of leafs, dead rhododendron flower buds, dead branches and in sever cases loss of the entire plant. Broadleaf evergreens are most vulnerable – especially Rhododendrons, Azaleas, Holly, Boxwood, Andromeda, and Mountain Laurel. To a lesser degree needled evergreens such as Arborvitae, Cypress, Alberta Spruce and Yews are also vulnerable. For the most part, deciduous plants (those that lose their leaves each fall) do not suffer winter dehydration (desiccation).
Wilt Stop: Wilt-stop is an anti-desiccant, an all natural spray that coats the greens with a thin wax that helps prevent moisture from evaporating from the needles and leaves
Two preventions that work:
Spray with an anti-desiccant
Right now - literally this weekend, when temperatures are 40 degrees or above - spray your broadleaf and needled evergreens with an anti-desiccant. The product we like best is called Wilt Stop. Spray it on the upper and lower leaf surfaces and it will provide an invisible waxy coating that will seal in moisture, protecting the plant from the drying winter winds that can cause browning, desiccation and death. This is particularly important for newly planted shrubs, container plantings, and any evergreen that is planted in an area where it is exposed to strong winter sun or wind.
Wrap with burlap
Newly planted evergreens, and those that are planted in exposed, windy areas may benefit from being wrapped in burlap for the winter. The best way to do this is to drive 3 or 4 stakes into the ground around the plant, wrap the burlap around the stakes, and staple or tie securely. If you want to protect an evergreen hedge, you can simply drive the stakes into the ground every 3 feet or so on both sides of the hedge and staple the burlap to the stakes, snug against the hedge, rather than wrap each plant individually. Evergreen hedges planted along the street may be exposed to road salt so it’s best to use a double layer of burlap for greater protection. Road salt can be very damaging to the foliage. Never use any type of plastic, as this material will heat up on sunny days, causing the foliage to burn.
Special note about Hydrangeas
Hydrangeas are also susceptible to desiccation. Flower buds that are located on the canes can also suffer winter damage. In this case, sprays and burlap are not the solution. Instead gently stuff straw or leaves in the middle of the canes, then tie up the canes and mound more straw or leaves around the outside. This cocoon should protect next years flowers from this winter’s wind and sun. Final note: do not uncover too early in the spring as tender buds could still be damaged during spring frosts.
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