The dense, multi-stemmed structure of arborvitae, particularly columnar varieties such as ‘Emerald Green’ or ‘Green Giant’ (Thuja species), makes them vulnerable to winter damage. Their upright or conical growth habit acts like a funnel, easily catching and accumulating heavy, wet snow or ice. The immense weight forces the branches outward, resulting in splaying or permanent breakage and deformation. Proactive measures taken before the first snowfall are the most effective strategy for preventing structural compromise and preserving the aesthetic form of the plant.
Pre-Winter Structural Preparation
Preparing arborvitae structurally is the most effective defense against snow load damage, primarily involving binding and thoughtful pruning. The most common preventative method is to gently bind the plant vertically using soft material like jute twine, durable cloth strips, or specialized netting. This binding creates a unified, narrower silhouette that is better equipped to shed snow rather than collecting it within the branch structure.
To secure the plant, begin by anchoring the twine at the base of the shrub near the trunk. Spiral the material upward, wrapping the branches snugly but not tightly, until you reach the top of the central leader. This spiraling technique compresses the branches, allowing them to support one another under stress. Use materials that are wide and soft to ensure they will not girdle, or cut into, the bark and branches.
Another important preventative step is structural pruning, performed during the dormant season before winter. Thinning the dense interior canopy allows greater airflow and provides pathways for snow to fall through the plant instead of accumulating on the exterior foliage. Removing weak, crossing, or excessively dense inner growth reduces the overall surface area where heavy snow can settle. This enhances the plant’s natural resilience, reducing the likelihood of major structural splitting.
Safe Techniques for Snow and Ice Removal
When a snow event is underway or has just finished, immediate, gentle intervention can prevent splaying and breakage. If heavy, wet snow has accumulated, use a long-handled broom to remove the load. The proper technique involves gently sweeping the broom upward, starting from the base of the branch and moving toward the trunk.
This upward motion encourages the snow to lift and fall away without pulling the already stressed branch downward, which could increase the risk of snapping. Alternatively, a light, upward tapping motion on the underside of the branch can dislodge the snow effectively. Repeat this process around the entire plant until the branches can return to a more upright position.
It is necessary to avoid aggressive actions when attempting to clear precipitation. Never attempt to forcefully shake or beat the branches, especially if they are frozen, as the wood becomes brittle in cold temperatures and will snap instantly. Do not use hot water to melt ice, since the sudden temperature change can shock the plant tissues, causing significant cellular damage. If the branches are coated in ice, wait for warmer temperatures or radiant sunlight to melt the ice naturally.
Post-Damage Repair and Recovery
If branches have splayed open after a storm, but are not broken, they can often be coaxed back into their original form. After the threat of severe weather has passed, use wide, flexible straps or soft ties to gently pull the splayed sections inward and secure them to the main body of the plant. The goal is to apply just enough tension to restore the vertical shape, holding the branches in position while the tree recovers its structural memory.
These recovery ties should remain in place for at least one full growing season, but must be removed within two seasons to prevent girdling as the plant thickens. For branches that have cleanly broken or splintered, proper horticultural pruning cuts are necessary to prevent disease entry and encourage healing. Prune the damaged limb back to a healthy lateral branch, or to the main trunk, ensuring a clean cut is made just outside the branch collar.
In the spring following the damage, providing optimal care will encourage the arborvitae to recover and fill in any voids. Apply a slow-release fertilizer designed for evergreens to encourage robust new growth. Consistent watering throughout the growing season is also important, as this supports the plant’s energy reserves for recovery and structural repair.