If you had Frostweed in your garden, you might have noticed a show a couple of weeks ago during the freezing weather. Frostweed, Verbesina virginica, forms ice crystals when the ground temperature is warm enough for the plant’s root system to be active. Moisture in the plant flows from the roots up into the stem, where the cold air freezes it. As the moisture in the plant freezes, the ice crystals push out through the stem. The result is something that looks like cotton candy, or cotton batting, or maybe even a bizarre insect nest.
Frostweed (Verbesina virginica). Photos by Meade LeBlanc, January 16, 2024.
Frostweed isn’t the only plant that can react this way to freezing temperature. The following photos, captured by Nancy Saint in January 2018, are of Saltmarsh Fleabane, Pluchea odorata. “I was very surprised when I walked out that frosty morning to see the fascinating frosty curls coming out of the stems,” said Nancy.
Saltmarsh Fleabane (Pluchea odorata). Photos by Nancy Saint, January 2018.
This article first appeared in Deep Roots Newsletter, February 2024.