Look, don't touch. Frost flowers will break or disappear if disturbed.
Seeing a frost flower first hand is a privilege afforded only to the early riser. Once exposed to the morning sun, they quickly disappear. Touch them and they shatter.
A frost flower is really neither "frost" nor "flower," but layers of ice squeezed from the stem of a plant.
You may be growing a few crystallofolia in your native wildflower garden. Frost flowers are so rare, it is possible that you don't even know they are growing in your garden. Late September is the perfect time to scout out some potential frost flower spots.
Sometimes these delicate sculptures are called ribbon ice or rabbit frost.
Find frost flowers in autumn or early winter, before the ground freezes.
Water continues to be drawn up the plant’s stem while the ground remains unfrozen.
Fall weather and temperature conditions must combine perfectly to encourage the “blooming” of frost flowers. You cannot pick frost flowers or gather a bouquet. The only way to capture them is on camera.
Rarely in September, usually in October, and possibly in November you can hunt for frost flowers. Find these elusive blooms by tagging along with an early morning deer hunter this season. Pictures are the only way to prove your frost flower prowess to late risers.
Before the ground freezes for the winter, but after plants are exposed to a hard frost, frost flowers happen. As plant sap or water freezes, it expands. That creates tiny fissures in the plant stems. As the liquid freezes and expands, it is forced out of the cracks or tears in the plant stalks.
The moisture is drawn through the cracks on the plant stems by capillary action. That sap freezes when it oozes out the stem and into the air, forming elaborate “petals.” This extrusion creates beautiful frozen petioles that are never the same.
A frost flower is created from the stems of plants or sometimes, wood. The elaborate patterns that curl and fold into flower-like-forms are where the frost flower got its name. It is also called frost castles, ice castles, ice blossoms, crystallofolia, feather frost and frost ribbons.
Late-blooming native wildflowers like yellow ironweed (Verbesina alternifolia) and white crownbeard (Verbesina virginica) can create frost flowers. White crownbeard is also known as frost beard. American dittany (Cunila origanoides) and longbranch frostweed (Helianthemum canadense) can also create delicate frost flowers.
Want to see them for yourself? Before that freeze, scout out the woods or along the creeks and look for ironweed. Then, you will be ready to return when the conditions are right for frost flowers.
While the ground remains unfrozen, water is drawn up the plant’s stem. Once it reaches the split, the water oozes slowly out and it freezes. Once the ground freezes, the plants can no longer draw moisture upwards and out through the broken stems. Frost flower season is over.
To learn more:
Missouri Department of Conservation — mdc.mo.gov/conmag/2000/10/frost-flowers
National Weather Service — crh.noaa.gov/lmk/?n=frost_flowers
My World of Ice, Dr. James R. Carter, Professor Emeritus — my.ilstu.edu/~jrcarter/ice/
Photos by Bill Roussel