Frost flower time
Depending upon whose weather forecast you trust (or which one comes true), by the time you read this and depending upon where you live exactly, valley or mountaintop, we will likely experience autumn 2021’s first freezing temperatures. That means it’s time for an annual phenomenon which occurs along with the first hard freezes of the season, called “frost flowers.”
At the base of the plant near the root, only two local native plant species produce twisting, fluted, extruding ribbons of ice or frost flowers. Bob Harms at the Plant Resource Center, University of Texas, Austin, coined a more formal term—crystallofolia. For the most detailed information on this frozen display of beauty see Harms pages at: w3.biosci.utexas.edu/prc/VEVI3/crystallofolia.html.
And if all else fails, you can just look-up “frost flowers” on Wikipedia. Google will point you to a website crystallofolia.com, but for better or worse, it’s gardening blog posts from a woman in Minnesota named Crystal who co-opted the term. Bad on you Crystal, though the website is truly harmless (as in no crystallofolia as described by UT’s Bob Harms).
One of the fascinating things about frost flowers is that they are only produced by a handful of plant species. Here in the Ozarks only two plant species produce them. One is known as white crownbeard or frostweed, a late summer- to fall-blooming member of the aster family usually about 3-5 feet tall, with winged-stems and not particularly showy white flower clusters.
After the first hard freeze, one will drive along streets or roadsides (along Grand Avenue and Dairy Hollow, for example), and at first glance you might think a pickup truck drove by scattering loose white plastic grocery bags along the roadside. Look closer, and you’ll realize that this is ice formed at the base of white crownbeard’s faded stalks. Come back later in the morning after they’ve received sunshine and above freezing temperatures, and the ephemeral frost flowers will be gone.
Usually at the same time, but often a little later, and lasting into the winter months, one will also find frost flowers at the base of American dittany (Cunila origanoides) a foot-tall, wiry-stemmed fall blooming woodland mint family member. Put your camera equipment outside (maybe in the trunk of your car), so the camera will be at ambient temperature (you can keep the batteries indoors), get up early, head out at sunrise, and enjoy photographic frost flowers.