What temperature damages most vegetables?

The tolerance of various vegetables to temperature fluctuations is greatly variable between different types of vegetables. Warm-season types such as tomatoes and peppers undergo cellular damage if temperatures fall below 50°F (10°C). Cold-hardy plants can survive in freezing conditions, but they have limitations in terms of their temperature tolerance. Identifying these temperature thresholds will help mitigate crop loss during unanticipated cold temperatures.

Ice crystal development in delicate plants leads to cellular injury. Plants adapted to warm conditions do not possess natural antifreeze compounds. Cellular damage occurs when there is a sudden temperature reduction. The result is usually blackened leaves and mushy stems. The damage is permanent when plants have been exposed to environmental temperatures below a low-temperature point for more than a few hours.

Cold-hardy adaptations include the accumulation of sugars and the synthesis of antifreeze proteins. For example, kale increases its sucrose concentration, thereby lowering the freezing point of the tissue. For spinach, the plant produces proteins that have thermal hysteresis properties. These adaptations help to prevent the formation of ice in the tissue down to a specific temperature. These adaptations are also protective when natural limits are exceeded.

Geographic considerations significantly impact vulnerability. Coastal grown vulnerabilities can develop with the cold, wet weather, causing frost heave. Vulnerabilities may arise in arid regions with freezing overnight temperatures after very warm days. Mountain zones may endure extended periods below freezing. Throughout all seasonal changes, pay special attention to local weather forecasts to know when to intervene.

Microclimate management is a practice that provides a buffer against temperature extremes. Sensitive plants can be protected by locating them near south-facing walls. Water barrels can hold daytime heat and then release it when nighttime cooling occurs. Windbreaks created with evergreen shrubs can also be beneficial. These techniques will provide 5-10°F of protection and can significantly extend the growing seasons.

Begin applying protection against low temperatures before experiencing critical levels. During the fall and spring, closely monitor forecasts and record damage threshold levels for each vegetable type. Your awareness and timely response can save you from disappointment and crop loss due to inadequate action.

Read the full article: Top 10 Cold Hardy Vegetables to Grow