Snow and ice present a dual threat to landscape plants, combining the crushing weight of frozen precipitation with the cellular damage caused by extreme cold. Heavy, wet snow can break branches, while freezing temperatures can lead to dehydration as water is locked away in frozen soil, a phenomenon known as winter desiccation. Proactive measures taken before a storm arrives significantly increase a plant’s ability to withstand these stresses and return to health in the spring.
Preparing Plants for Winter Weather
The most effective defense against winter damage begins weeks before the first forecast of snow or a hard freeze. Deep watering is the single most important preparatory step, particularly for broadleaf and needle evergreens. These plants continue to lose moisture through their foliage all winter long, and if the ground is frozen, they cannot replenish it, leading to “winter burn” or browning. Watering deeply and thoroughly in late autumn, until the ground is about to freeze, ensures the plant’s tissues are fully hydrated, reducing the risk of desiccation.
Moist soil also holds significantly more heat than dry soil, providing a buffer that helps insulate the roots from extreme temperature fluctuations. Applying a two- to three-inch layer of organic mulch around the base of trees and shrubs helps maintain this stable soil temperature, which also prevents the damaging expansion and contraction of the ground known as frost heave. A light structural pruning to remove dead, diseased, or weak branches eliminates potential points of failure that would otherwise snap under a heavy snow load. Container plants should be moved to a protected, unheated location like a garage or covered porch, as their root systems are more vulnerable to freezing solid than those planted in the ground.
Physical Protection Strategies
Temporary physical barriers protect plants from snow accumulation and cold when severe weather is expected. For delicate shrubs and trees, the goal is to prevent heavy snow from resting directly on the foliage. Materials like burlap, horticultural fleece, or old sheets can be draped over plants, but they must be supported by stakes or a temporary frame to avoid crushing the structure. This tenting method creates a pocket of insulating air and traps radiant heat rising from the soil beneath.
For tall, columnar plants like arborvitae or upright junipers, which are prone to splaying open under weight, a simple binding technique provides structural integrity. Loosely spiraling rope or heavy twine from the base to the top gently holds the main branches closer together, preventing them from catching and breaking under heavy snow or ice. Smaller, low-growing plants and perennials benefit from mini-shelters constructed from tomato cages wrapped in burlap or dedicated garden cloches. If plastic sheeting or non-breathable covers are used, ensure they are removed or ventilated during sunny or warmer spells to prevent excessive temperature build-up and condensation.
Post-Snowfall Assessment and Care
Once the storm has passed, immediate and careful action can mitigate long-term damage. Avoid aggressively removing snow; heavy or frozen branches should never be shaken, as this can cause them to snap instantly. Instead, use a soft broom to gently push snow off the branches with upward strokes, lifting the weight without forcing the frozen wood downward. Avoid using de-icing salts near plants, as the runoff can severely damage roots and prevent moisture absorption.
After the snow melts, assess plants for broken limbs or split crotches. Any broken branches should be pruned back to a healthy joint using a clean cut to prevent disease from entering the wound. Check for frost heave in perennial beds, where the freeze-thaw cycle has pushed roots out of the soil; gently firm the soil around the base to heel the plant back into the ground. Remove protective coverings once the threat of sustained freezing temperatures is gone to restore air circulation and sunlight. If the soil is no longer frozen, providing a deep watering can help rehydrate plants that suffered moisture loss during the cold period.