Arborvitae (Thuja species) provide year-round structure and privacy. However, these evergreen plants are susceptible to damage from harsh winter weather, necessitating protective measures in certain climates. Wrapping arborvitae with burlap is a widely adopted practice to shield them from seasonal stressors. Effective protection relies on understanding the threats and executing the wrapping process at the correct time.
Identifying Specific Winter Threats to Arborvitae
Arborvitae foliage is vulnerable to moisture loss even when dormant. Desiccation, or “winter burn,” occurs when cold winds and bright winter sun cause needles to transpire moisture faster than roots can replenish it. This imbalance is compounded when the ground is frozen, preventing water absorption, which leads to browning, particularly on windward or south-facing sides.
Heavy snow and ice can cause structural harm. Upright varieties are prone to having branches splay outward or split completely under a substantial snow load. Reflected light off snow can also exacerbate desiccation.
Wildlife, especially deer, pose another threat. When natural food sources are scarce, deer browse on the accessible evergreen foliage. This strips the tips of branches, often leaving severe damage and permanent gaps. Burlap serves as a physical barrier against deer and helps mitigate salt spray damage near driveways and walkways.
Optimal Timing for Burlap Application
Determining the appropriate time requires waiting for plant dormancy while acting before the onset of damaging weather. Wrapping must be postponed until the plant has fully hardened off, meaning waiting until after several hard, sustained frosts have occurred. This ensures the plant is no longer actively growing and has entered its dormant state.
The ideal window for application is typically late fall or early winter, before the ground freezes solid. Once the soil is deeply frozen, the roots cannot take up water, making the plant susceptible to desiccation. Applying the burlap before this point allows the plant to benefit from late-season moisture.
Preparation should begin with a deep watering in late autumn, right before the expected permanent freeze. This soaking saturates the soil and tissues, providing a reserve of moisture to combat drying effects. The burlap can then be applied once temperatures are consistently below freezing, but before the worst of the snow and ice arrives.
Proper Wrapping and Securing Techniques
Proper winter protection requires using natural, breathable burlap fabric, not solid plastic or tarps. Non-breathable materials trap moisture and inhibit air circulation, which can lead to fungal diseases and mildew.
There are two primary wrapping methods. For maximum protection against deer browsing and heavy snow load, the arborvitae should be loosely wrapped in a spiral fashion from the base to the top, gently bundling the branches inward. If desiccation is the main concern, a full enclosure is beneficial, though some gardeners leave the top slightly open for airflow and light exposure.
To secure the material, durable garden twine or specialized zip ties should be spiraled from the bottom upward. The branches should not be cinched too tightly, as this can damage the foliage and impede the plant’s natural movement. The goal is to protect the structure and foliage, not to constrict the plant.
Burlap Screen Method
An alternative method, preferable if desiccation is the sole concern, is constructing a burlap screen or fence using wooden stakes. Drive stakes around the arborvitae and staple the burlap to them, creating a protective wall. This structure prevents the burlap from touching the foliage, which is beneficial as direct contact can hold moisture.
Removal Timing and Spring Transition
The protective burlap should be removed as soon as the plant transitions out of deep dormancy. This timing is typically in early spring, around mid-March to early April, once the threat of sustained, hard-freezing temperatures has passed. Removing the burlap too early risks exposing the plant to a late-season hard frost, which can damage newly awakened tissues.
Leaving the wrap on too long is also risky. Prolonged wrapping into warmer spring temperatures can cause the plant to overheat and transpire excessively, potentially leading to damage. Extended blockage of sunlight can weaken the plant and increase the likelihood of mold or mildew forming in trapped moisture.
The removal process should be performed gently, carefully cutting away the twine and peeling the burlap away from the foliage. After removal, inspect the plant to identify any winter-damaged, brown, or broken branches for selective pruning. Providing a deep spring watering once the ground has fully thawed helps the arborvitae rehydrate and transition into the active growing season.