Frost Flowers, Also Known as Ice Flowers
Frost flower formations are also referred to as “ice flowers”, “ice blossoms”, “frost castles”, “frost beard”, “ice castles”, or “ice ribbons”.
The formation of frost flowers, is apparently dependent on a freezing weather condition occurring when the ground is not already frozen. The sap in the stem of the plants will expand (water expands when frozen), causing long, thin cracks to form along the length of the stem. Water is then drawn through these cracks via capillary action and freezes upon contact with the air. As more water is drawn through the cracks it pushes the thin ice layers further from the stem, causing a thin “petal” to form. The “flowers” will continue to grow as long as the air is below freezing and the ground is warm enough for water to be drawn up through the plant. The petals are normally very thin and delicate and will be gone shortly after the sun hits them.
Plants that often form frost flowers are white crownbeard, commonly called frostweed, tickweed, or ice-plant. These waist- to shoulder-high plants grow in dense patches in the moist, shaded soil of river or creek bottoms and form heavy undergrowths in the shade of large trees.