Junipers are resilient evergreen shrubs and trees that bring year-round beauty to many landscapes. While known for their toughness and ability to withstand harsh conditions, understanding their specific needs during winter ensures they remain healthy and vibrant through colder months.
Juniper’s Winter Appearance and Adaptations
Junipers naturally adapt to cold temperatures, often displaying noticeable changes in their appearance. Many varieties undergo a color transformation, shifting from green to purplish, bronze, or brownish tones as winter approaches. This change is a natural physiological response, due to anthocyanins, pigments that act like a plant’s internal antifreeze and sunscreen, protecting foliage from intense winter sun and cold. This color change indicates the plant is preparing for dormancy, a period of reduced metabolic activity where growth slows significantly.
Beyond color changes, the physical structure of junipers also helps them endure winter. Their dense, layered branching patterns allow them to shed snow effectively, preventing excessive accumulation that could lead to breakage. Junipers are cold-hardy, with many varieties able to withstand extremely low temperatures. This hardiness is supported by their robust root systems, which continue to function even in cold soil, though at a reduced capacity.
Essential Winter Care for Junipers
Proper care for junipers before and during winter is important for their health. Proper watering is especially crucial in late fall, ensuring plants are well-hydrated before the ground freezes solid. Deep watering allows roots to absorb and store moisture, mitigating winter desiccation, where plants lose water but cannot replenish it from frozen soil. During dry winter spells when the ground thaws, occasional deep watering can also benefit the plant.
Mulching is another beneficial practice that insulates the root zone. A layer of organic mulch, typically 2 to 3 inches deep, helps maintain a more consistent soil temperature, preventing extreme freezing and thawing cycles that can heave plants out of the ground. It also helps retain soil moisture. Keep mulch a few inches away from the plant’s trunk or base to prevent moisture buildup and rot. Avoid late-season fertilization, as it promotes tender new growth vulnerable to frost damage. Fertilization is best done in late winter or early spring before new growth emerges.
Protecting Junipers from Winter Damage
Junipers face specific winter threats requiring protective measures. Winter burn, or scorch, occurs when cold winds and sun cause evergreens to lose moisture faster than their frozen roots can absorb it, leading to browning or reddening of foliage. Adequate pre-winter hydration is key to mitigate this. For junipers in exposed, windy, or sunny locations, a burlap screen can deflect harsh winds and sun, though direct wrapping is not recommended as it can trap moisture.
Heavy snow and ice can weigh down branches, potentially causing breakage. Upright juniper varieties are particularly susceptible to this. Gently brushing accumulated snow off branches with an upward motion can help prevent damage, but avoid forcing frozen branches. Tying branches of multi-stemmed junipers loosely with rope or fabric before winter offers support and helps them shed snow more easily.
De-icing salts used on nearby walkways or driveways can harm junipers, causing foliage burn and root damage. If possible, use alternative de-icing products or create physical barriers to protect plants from salt spray and runoff. Low-growing junipers are also susceptible to damage from voles and rabbits, which may gnaw on bark or foliage when food is scarce. Protective fencing, such as hardware cloth, can deter these animals.