Frost Flowers: Nature’s Exquisite Ice Extrusion
It is as beautiful as it is rare. A frost flower is created on autumn or early winter mornings when ice in extremely thin layers is pushed out from the stems of plants or occasionally wood. This extrusion creates wonderful patterns which curl and fold into gorgeous frozen petioles giving this phenomenon both its name and its appearance.
Conditions have to be just so for frost flowers to form. Early winter and late autumn are the optimum time to come across them as although the weather conditions must be freezing it is vital that the ground is not.
As the temperature gets to freezing or below the sap in the stem of the plants will expand. As it does so the outer layer of the stem comes under increasing pressure and microscopically thin cracks, known as linear fissures, begin to form. These will finally give way under the pressure of the sap and split open.