Winter wrapping protects landscape plants from harsh weather, ensuring their survival and vigorous return in the spring. It shields against environmental damage, including the dehydrating effects of cold winds, sunscald on tree bark, and the desiccation of evergreen foliage. This process is especially beneficial for newly planted specimens, less hardy varieties, and plants in exposed locations. Proper wrapping involves correct timing and selecting the right materials to create a protective, breathable barrier.
Timing and Preparation for Wrapping
The optimal time to begin wrapping is in late fall, after the plant has entered full dormancy, typically following the first hard frosts. Waiting until after deciduous foliage has dropped ensures the plant is shut down for the season. Wrapping too early, while the weather is mild, can trap excessive moisture and heat, encouraging fungal diseases and rot.
A preparatory step involves ensuring the plant is well-hydrated before the ground freezes solid, as dry roots are susceptible to winter burn. Evergreens, which lose moisture even in cold weather, benefit from deep watering until the soil is no longer workable. Light pruning of dead, diseased, or damaged branches is also recommended to prevent friction damage against the wrap or entry points for pests.
Selecting Appropriate Protective Materials
Choosing the correct material is essential for effective winter protection, as the barrier must protect without suffocating the plant. Breathable materials, such as natural burlap and horticultural fleece, are preferred because they allow air and moisture exchange, preventing humidity buildup and fungal issues. Burlap is effective for screening evergreens from intense sun and wind while permitting light to reach the foliage.
Plastic sheeting should be avoided for a complete wrap because it is non-breathable and can cause overheating followed by freezing condensation, creating a damaging microclimate. Heavy-duty plastic or tarps can be used as a windbreak layered over a breathable cover or to create a roof structure to shed heavy snow and ice. Securing materials, like jute twine or weatherproof zip ties, must be strong enough to hold the covering taut against winter winds without damaging bark or branches.
Step-by-Step Wrapping Techniques
The wrapping technique varies by plant structure, but the principle is to prevent contact between the wrapping material and the foliage or bark.
Trunks
For young, thin-barked deciduous trees, the trunk should be wrapped from the base up to the first major branches using commercial tree wrap or strips of burlap. This protects the bark from sunscald, which is caused by rapid temperature fluctuation when the winter sun warms the bark and the temperature drops quickly at night.
Upright Evergreens
Upright evergreens, such as arborvitae, are often protected by gently binding the branches together with soft twine in a spiral motion, moving from bottom to top. This conical shape reduces the surface area exposed to wind and prevents heavy snow or ice from splaying the branches. A burlap or fabric covering is then draped over a simple wooden stake frame or teepee structure built around the plant, ensuring the material does not tightly press against the needles.
Container Plants
Container plants require protection for their root systems, which are more susceptible to freezing than those in the ground. Potted plants should be grouped together against a sheltered wall. The pots themselves should be wrapped with insulating materials like bubble wrap, burlap, or straw to buffer the roots from extreme cold. For added insulation, the base of the plant can be topped with a thick layer of shredded mulch or straw.
Removal and Post-Winter Care
The timing for removing winter protection should occur when the risk of a hard freeze has reliably passed and consistent temperatures are above freezing. This typically falls between mid-March and late April, depending on the geographical location. Removing the covering too early leaves the plant vulnerable to a late-season cold snap, while removing it too late can cause the plant to overheat and break dormancy prematurely.
It is beneficial to unwrap plants on a cloudy day to allow the foliage to gradually re-acclimate to direct sunlight, reducing the risk of sun scorch. Once the wraps are off, inspect the plant for signs of pest damage or fungal growth. A light spring feeding with a balanced fertilizer can help replenish nutrients and encourage new growth.