Even though indeterminate tomatoes are perennials, they are grown as annuals because of their intense aversion to cold. Not only do tomatoes stop producing as temperatures sink, they’re killed entirely by hard frosts and freezes.
Tomatoes’ Natural Climate
Tomatoes were originally bred from subtropical plants arising in a region covering parts of Peru and Ecuador and spread northward to Mexico before Columbus set foot in the Western hemisphere. In such regions, tomatoes climbed, bolstered from the steamy, but frost-free temperatures that frequently fell within their optimum temperature range. Tomatoes spread to Europe, in which they had been initially feared, then afterwards adored for their sweet fruits. Unfortunately, these plants are still adapted to these climates in which they originated, making long periods of cool temperatures — under 55 degrees Fahrenheit — often as damaging as frosts. Tomato plants develop and create best between 60 and 85 degrees Fahrenheit.
How Frost Kills
Frost generally happens on still nights when the ambient temperature drops below or near freezing. Exposed plant cells are damaged when water vapor from the atmosphere condenses on plant surfaces, then freezes. Condensation types because plant cells are originally warmer than the surrounding atmosphere, even though they cool quickly in the evening. Often these events happen quickly from the coldest portion of the night, making frost only briefly. Unfortunately for tomatoes, even just a brief stint of freezing is sufficient to finish the growing season.
Protecting Tomatoes From Light Frost
If a mild frost is predicted, you could have the ability to protect your impurities in the chill injury or freeze damage it may cause. Depending on the size of the plants, you may use an assortment of covers to insulate your plants from the colder atmosphere outside, from large cardboard boxes to get smaller patio tomatoes to large, clear plastic tents for larger garden varieties. Remove the cover in the morning to prevent accidental overheating.
Ripening Tomatoes Indoors
When frost threatens, a few gardeners uproot their plants and bring them indoors to ripen the fruit that remains on the vine. This will only work with completely formed fruits that are only barely beginning to turn red, so in the event that you decide to hang your tomatoes upside down in the basement, then pick off any underdeveloped fruits. Your tomato plant will die, but the vine creates a handy place to store fruit as it finishes ripening.