Needle ice forms when the temperature of the soil is above 0 °C (32 °F) and the surface temperature of the air is below 0 °C (32 °F). Liquid water underground rises to the surface by capillary action, and then freezes and contributes to a growing needle-like ice column.

What causes ice ribbons?

Air temperatures need to drop below freezing while the liquid inside the stem remains warmer. ... Once ice forms on the outside of the plant stem, water flows out, freezes, and adds to the ice, creating the long ribbons.

Why does ice freeze in columns?

During ice segregation, ice forms at or just below the soil surface, where water meets the colder air and freezes. As more water from the soil moves up towards the ice through capillary action, it freezes and expands, and the ice is pushed up out of the soil, forming long, fragile columns that poke out of the earth.