Common ivy (Hedera helix) is a durable evergreen vine commonly seen clinging to walls or as a groundcover. When winter arrives, the plant does not die back, but it fundamentally changes its activity level. The direct answer to whether ivy grows in winter is no; it survives the season by ceasing active growth and entering a deep state of physiological rest to endure freezing temperatures and low light.
Understanding Dormancy
The lack of growth during the colder months is a plant survival mechanism known as dormancy, which is triggered by environmental cues. The primary signals that induce this winter rest are the combination of shortening daylight hours and consistently low temperatures. This process is how many perennial plants manage to withstand harsh seasons.
Ivy responds to these cues by drastically reducing its metabolic rate, essentially putting its biological functions on pause. The plant shifts its energy expenditure away from cell division and the production of new leaves and stems. Instead, the limited energy reserves are directed toward simple maintenance and protecting existing root and tissue structures.
Ivy achieves cold hardiness by altering the composition of its cells. Before the deepest cold sets in, the plant concentrates solutes within its cells, which acts as a natural antifreeze to prevent damaging ice crystals. This internal preparation allows Hedera helix to tolerate temperatures as low as -28°C in some hardy varieties.
Visual Changes During Cold Weather
Ivy is an evergreen, retaining its foliage throughout the year, unlike deciduous plants. Despite dormancy, the leaves undergo noticeable visual changes in response to cold stress and increased light exposure. This is a protective measure, not a sign of the plant dying.
The normally deep green foliage may take on a bronze, reddish, or even purplish hue as temperatures drop. This color change is caused by the increased production of pigments called anthocyanins within the leaf tissues. Anthocyanins act like a plant’s internal sunscreen, helping to shield the chlorophyll from excessive light exposure and prevent photooxidation damage in freezing conditions.
This temporary shift in pigmentation helps the ivy protect its photosynthetic apparatus until warmer conditions return. In some cases, leaves exposed to harsh winter winds or intense, drying sun may turn brown and appear desiccated. This browning is a form of injury, but the root system usually remains healthy, ready to push out new green growth in the spring.
Practical Winter Maintenance
Even though ivy is dormant and requires less attention than in the growing season, a small amount of maintenance can significantly improve its winter survival. The most frequent cause of winter damage is not freezing cold, but desiccation, which is the drying out of the plant’s tissues. This occurs when the ground is frozen, preventing the roots from taking up water, while winter winds continue to pull moisture from the leaves.
Occasional winter watering is important, especially during dry spells when the soil is not frozen. Check the soil moisture and provide water when the top two to three centimeters feel dry. Applying a layer of organic mulch, such as shredded leaves or wood chips, five to seven centimeters deep around the base of the plant, insulates the roots from severe temperature fluctuations.
Younger or container-grown ivy is much more susceptible to root damage from the cold. Potted plants should be moved to a sheltered area, such as a garage or against a wall, to protect the roots from deep freezing. Protecting exposed plants from intense wind and sun with a temporary covering, like a breathable frost cloth, can also minimize the risk of desiccation damage.