What part of the vine is most at risk during a winter freeze?

The graft is the point where the scion (the part of the vine that produces the fruit) is joined to the rootstock (the part that provides the vine's root system). This area is particularly vulnerable during winter freezes because it represents a critical junction between different parts of the vine that may respond differently to extreme cold.

During freezing conditions, cellular damage can occur due to ice formation within the tissue, which can severely affect the grafting site and its ability to transport nutrients and water effectively. If the graft sustains damage, it can disrupt the plant's overall health and reduce its capacity to rejuvenate in the spring, potentially leading to dieback or poor fruit production.

While other parts of the vine, such as roots, trunk, and leaves, are also at risk from cold temperatures, the graft site is particularly susceptible because of the stress that occurs during the grafting process, which can leave it less resilient to harsh environmental changes. This makes the graft a critical focus for vine health during the winter months, where protection and careful management can be influenced to safeguard this essential area.