Why do vegetables and fruits get damaged during severe frost?

During severe frost, when temperatures drop significantly below freezing, vegetables and fruits can suffer significant damage due to the formation of ice crystals within their plant tissues. This damage primarily occurs in two ways:

1. Ice Crystal Formation: As temperatures drop, the water content within the cells of vegetables and fruits starts to freeze. This water forms sharp ice crystals that expand and rupture the delicate cell walls, damaging the plant's cellular structure. The integrity of the cell membranes is compromised, leading to leakage of cell contents and loss of essential nutrients.

2. Dehydration: The process of ice crystal formation also leads to dehydration in vegetables and fruits. When water freezes, it expands and separates from the remaining cellular components. This separation disrupts the water transport system within the plant, hindering the movement of water and nutrients throughout the tissues. As a result, the plant becomes dehydrated and loses its turgidity, causing wilting and shriveling.

The extent of damage depends on several factors, including the plant's cold hardiness, the severity and duration of the frost, and the specific plant tissues involved. Some vegetables and fruits are more susceptible to frost damage than others. For example, tender crops such as tomatoes, cucumbers, and squash are more vulnerable compared to hardier vegetables like kale, spinach, and Brussels sprouts.

To mitigate frost damage, several protective measures can be taken. These include using row covers or frost blankets to insulate plants, applying water to release latent heat as it freezes, and choosing frost-tolerant varieties of vegetables and fruits.