Have You Ever Seen Frost Flowers?
Frost flowers are delicate white ice formations that develop at ground level around the dry stems of plants. They go by many other names, including ice flowers and ice ribbons.
An amazing sight
The first time I saw frost flowers, years ago, was the day after Halloween. My husband Allan had seen “white things” all over our hillside and asked me to help “clean up the mess.” It looked like someone had strewn trash on our property — not an unusual occurrence during our early days on this farm.
My first impression on seeing “the mess” was that it was blown tissue that got hung up in the weeds. Since it was the day after Halloween, I thought one of our neighbors had likely been toilet papered. But our nearest neighbor isn’t that close.
I next thought the white things might be grass spider funnel webs. Sometimes in the early morning we see numerous white funnel webs littering the grass. But by November it gets pretty cold for spiders.
So Allan and I were astounded when we got close enough to see the ice formations. Once you see them up close, you can readily recognize them from a distance.
How frost flowers form
A frost flower is an ice formation wrapped around the base of a dry plant stem that appears when moisture in the soil remains above freezing while the air temperature falls below freezing. Such conditions are optimal on a clear night with no wind.
When conditions are right, capillary action draws ground moisture up through certain plant stems, causing the dry stems to expand and split vertically. Each thin ribbon-like ice sheet curls as it expands outward, creating white flower-like structures. Just like snowflakes, no two frost flowers are alike.
The majority of frost flowers appear on the first frosty morning in autumn. They don’t occur twice on the same plant, but they may appear on different plants on other days. So potentially you can enjoy the sight on more than one day each year.
Since they require moisture in the soil, they don’t develop at all during years when conditions are droughty. They also don’t appear right after rain or snow. The best chance of seeing them is when the ground is warm, the air is dry, and the nighttime temperature drops low enough for a light freeze.
Depending on the weather, I start looking for frost flowers around the first of November. Sometimes I find hundreds. Sometimes only a few. Some years none. I thought 2022 was going to be a no-flower year, but a few finally appeared on the 14th, and then some more on the 18th and again on 19th.
Where to look
The flower forming process works only on the dried stems of a few specific plant species, most notably these:
- Dittany (Cunila origanoides), found in central and eastern states
- White Crownbeard (Verbesina virginica) in central and southeastern states
- Yellow Crownbeard (Verbesina occidentalis) in the southeast
- Yellow Wingstem (Verbesina alternfolia) in central and eastern states
- Canada Frostweed (Helianthemum canadense) throughout North America except the deep South
The easiest way to identify these plants is to look for them when they are in bloom and note where you saw them. Once they die back, the easier ones to identify are crownbeard and wingstem. Their stems typically have several vertical wing-like structures running up the entire length.
Frost flowers melt pretty fast once the sun comes out, so you have to look for them in the early morning. As soon as they start melting they lose their exquisite detail before disappearing altogether.
Documentary videographer Chris Korrow of Kentucky made an amazing time-lapse video show how frost flowers form. His website includes a 30-second sample from his video.
If you have never seen frost flowers, I hope some day you will. They are truly an amazing wonder of nature.
