Skullcap Hosts Frost Flowers

Frost flowers on Skullcap

Ruby Ball of Audubon, Missouri Native Plant Society and seemingly every other nature connected organization is always an astute observer of all things wild.  It makes sense that she would be one to report a new species hosting frost flowers.  Here is her report:

"You may want to add Skullcap to your list of frost flower plants.  A couple years ago the skullcap at the front door of the Nature Center had frost flowers 2 or 3 days in a row." 

Missouriplants.com

Skullcap refers to the Scutellaria species, Lamiaceae, which are more fully described at this Purdue horticultural site. The plants she describes at the Nature Center are downy or hoary skullcap, Scutellaria incana, a member of the mint family.  They are found across the Eastern US as well as in southern Missouri. 

In addition to a source of nectar, S. incana serves as a host plant for a specific species of moth, Caloptilia scutellariella.

There are good pictures and plant descriptions at Missouriplants.com.

Frost Flowers Bloom Along Bull Creek

Split epidermis of Verbesina virginica

We had our first frost flower "bloom" on Bull Creek last Saturday, October 27th.  It was ironic that it was the only day over several months that we had to be out of town and missed the excitement.  Fortunately frost flowers leave behind their incriminating evidence so we can tell that they were here.

The tell-tale long strips of split epidermis extended up to 18" high on the stalks of Verbesina virginica.  The temperature was forecast to be 28 degrees that night.  Deep in Bull Creek valley the sun only reaches the valley floor around 9 AM and it is shaded by 5:30 PM.  For this reason, it is almost always colder at night than the surrounding plateau.

Last year we had an unseasonally warm winter and the roots never froze.  We documented 40 mornings where there were frost flowers. (Yes, it is a little compulsive to keep track of each day's blooming but I didn't apparently have anything else to do at the time.)  The long term forecast is for another mild winter so I will start the count again.   I promise I won't blog about each one.

Do you grow Frost Flowers?

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Do You Grow Frost Flowers?

Have you ever heard of "frost flowers"? If so, you had to get out early in the morning during the first few hard frosts. Frost flowers, also known as "ice ribbons", are formed by super cooled water being extruded through plant stems and freezing the minute they hit the cold air. They are beautiful, delicate and transient, destined to disappear when the temperature rises – or before – if the sun hits them for a few minutes.

Frost Flowers in our area occur regularly on the stems of White Crownbeard, Verbesina virginica, and Yellow Ironweed, Verbesina alternifolia * as well as dittany, Cunilaoriganoides. These are native species found in much of the eastern US, usually found in disturbed soil and along roadsides. 

There are a few vague reports of finding frost flowers on other plants, mainly coming from Europe.  I am trying to compile a list of other plant species that produce frost flowers, no matter how small the "blossoms." It is important to be able to identify the parent plants which may otherwise be unrecognizable late in the season. As members of the Master Gardener organization, you know your plants and likely have a wide variety in your plantings.

Here Is Where You Come In:
 Visit your garden early on the morning of the first or second hard frost (below freezing through the night at temperatures below 28 degrees F) and look around the base of your plants. If you see ice ribbons on other new plants, identify the plant, preferably by genus and species, and if possible photograph the frost flowers if even with your phone. Then email me with your findings at frostflowers@sbcglobal.net. Your findings and pictures will be posted on a new blog at Frostflowerstudy.blogspot.com, either anonymously or with attribution as you choose.

I am a retired physician, involved in both Missouri Master Naturalists and Friends of the Garden. I have been in frequent contact with several experts from Michigan to Texas who have published information on frost flowers. Their papers are found below, along with frost flower pictures. 

Reports of your discoveries can expand our knowledge of these wondrous and mysterious frost flowers. Consider: no planting, fertilizing or watering, just an extra cup of coffee or tea with a warm coat for a 5 minute brisk walk in your own garden… and all in the name of science!

* 2013 Update
Doubt has been expressed about V. Alternafolia producing frost flowers.  The last two years we have been watching our V. Alternafolia along Bull Creek and have found no evidence of frost flower development in multiple environments.

Check out the following resources for more information on frost flowers:

scientificamerican.com/  

Dr. James Carter's Encyclopedic site 

/w3.biosci.utexas.edu/prc/VEVI3/crystallofolia.html

Bob Kipfer

Springfield Plateau Chapter of Missouri Master Naturalists

Blog at springfieldmn.blogspot.com