Frost Flowers

By Katherine Schlosser

There is something peaceful about a frosty pre-dawn morning. On the morning that I wrote this, I waited at the front door for our latest grand-dog to arrive. We keep him during the day while our daughter and son-in-law work, he providing as much company for us as we do for him. The sky was just turning a rosy pink near the horizon, but overall it was cold and cloudy.

Shivering as I stood looking out the door, a glimpse of white caught my eye.  My first thought was squirrels had again torn open the chairs on the deck, ripping out stuffing to line their nests. Walking down the steps to retrieve the wisps of cotton, I realized these are FROST FLOWERS!!

These fleeting beauties look as though they are made of cotton candy and are not flowers at all. They are found on those days when the ground is still warm and the air suddenly drops below freezing. This morning it was 30°F, humidity 66%, dew point 18°F, and the wind was still. You also need a few plants that, though they may have died above ground, still have roots that are sending water up the stems through capillary action.  When these conditions exist, and you search diligently before the sun rises, you might find a frost flower.

The frost flower is formed as sap is pumped up the stem of the plant. As the sap reaches a break in the old stem, or ruptures the dried stem, it seeps out and freezes as it hits the cold air. As more sap moves up, the ice is extruded, often forming odd ribbon-like shapes, sometimes curling around and forming what can even look like petals. These little icy confections are incredibly fragile, some very thin and melting at the slightest touch or at the first hint of sunlight.

Among our native plants that can form frost flowers are white crownbeard (Verbesina virginica), yellow ironweed (Verbesina alternifolia), and frostweed (Helianthemum canadense). Mine, as pictured, is growing from common dittany (Cunila origanoides).

You have to be up early to find them and lucky to boot. It is possible that other species can “grow” frost flowers when the conditions are right. The challenge is to get out and find them, which means walking through the garden or woods before the sun rises and while it is cold, watching diligently for the fantasy flowers that look like spun glass. They are magical, and while not rare, neither are they common.  

I have grown Cunila for five years and this is the first time I’ve seen frost flowers. Conditions have to be perfect…and it was worth the wait.

Photo Credits: 1) Frost flower on white crownbeard (Verbesina virginica) (Tanya Zastrow) 2) Yellow ironweed (Verbesina alternifolia) (Katherine Schlosser) 3) Common dittany (Cunila origanoides) (Kathy Schlosser) 4) Frost flower on Cunila origanoides (Kathy Schlosser)

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Katherine Schlosser (Kathy) has been a member of the NC Unit of The Herb Society since 1991, serving in many capacities at the local and national level.  She was awarded the Gertrude B. Foster Award for Excellence in Herbal Literature and the Helen deConway Little Medal of Honor.  She is an author, lecturer, and native herb conservation enthusiast eager to engage others in the study and protection of our native herbs.