Supercooling Helps Plants Resist Frost

When a solution's temperature falls below freezing point without ice crystals forming, it is said to be supercooled. Some plants are able to do this, and so can withstand freezing temperatures (many fish can do this as well). We saw recently how plants can avoid ice damage by removing fluid from the inside to the outside of their cell walls, where it can freeze between the cells without causing damage.

This article not only illustrates supercooling, it also shows how the latent heat of fusion released by this liquid as it turns to ice raises the temperature to the extent of 80 calories per gram of ice formed (This also illustrates the usefulness of spraying crops with water on the evening before a frost).

It also mentions that plants induce this supercooling by producing such compounds as sugars, amino acids and other solutes; also that plants produce antifreeze proteins and other low molecular weight compounds, which 'provide freeze tolerance by inhibiting ice crystal growth and the nucleation of ice crystals' (crystal structures form around a nucleus - usually a solid one such as dust (though obviously not inside a cell)).