Needles of Ice Growing on Wood

Haareis, Kammeis, Silk Frost, Pipkrake or ?


Dr. James R. Carter, Professor Emeritus

Geography-Geology Department

Illinois State University, Normal, IL 61790


  I have a collection of web pages showing what are sometimes called Ice Flowers, Frost Flowers and Ice Ribbons growing on vertical plant stems.  In 2006 Geoff Gaynor of Wales sent me an email with photos of some ice formations he had observed.  The ice in his photos is similar to my ice flowers but is on woody material, usually on the ground.  Since then I have seen photos from other sites showing similar displays of ice. This web page is essentially organized in chronological order based on when I have gained my information. 

Geoff gave me permission to show some of his images.  Note that the first 3 images belong to Geoff Gaynor and proper credit belongs to him.  The photo below shows the piece of wood with ice growing out from it.  The leaves give a measure of scale.  Note that the wood is exposed in these photos and not covered with bark where we see the ice.

Below we see a blossom made up of individual threads of ice. 

The photo below shows more of the same but it is more difficult to distinguish the individual threads of ice, or needles of ice.  In this case I have trouble seeing the wood.

The examples from Geoff in Wales are very similar to the displays of ice bobbi fabellano found along the Elwha River, on the Olympic Peninsula, Washington, below.  Again, give credit to her for these images.

In the photos above and below it appears that the piece of wood is not in contact with the soil surface.  In the example below the individual needles or threads of ice are very distinct.

In the large blossom below the individual needles of ice are very distinct and we can easily see the wood from which they emerge. 

In her email to me bobbi fabellano called this "silk frost," a name she heard from others,  She proposed the name "cotton candy frost" which is quite appropriate in many ways.   While the term frost is used frequently as part of such names, these ice formations are not a product of frost.  Frost comes about by moisture from the air being deposited on surfaces.  As such frost is quite amorphous and would never appear as fine needles like we see here. 

This ice comes up from the wood.  These events happen in the fall and winter when the soil is still relatively warm and above freezing.  As the temperature of the surface falls below freezing the water at the top of the wood turns to ice.  It is likely the water at the top of the wood becomes super cooled so that when it seeps out through small holes in the wood surface it immediately forms an ice crystal.  As more water seeps through those holes the crystals keep growing, producing the needles we see in these photos. 

A. Hillefors wrote about “Needle Ice on Dead and Rotten Branches” in Weather, 1976 (31, pp. 163-168).  He observed these in Sweden and notes they occur on branches of Beech.  He notes that when such ice forms in soil it is known as "pipkrakes" in Sweden and as "kammeis" in Germany.  He considered his ice on Beech to be a peculiar form of pipkrakes.

Hillefors has two small black/white photos of the ice formations that seem to be similar to the examples above.  But, he was not the first to have written about such ice formations.  A report on the meeting of the Physical Society in Berlin, in the March 13, 1884, issue of Nature includes a discussion from Prof. Schwalbe on what we now call needle ice and ice flowers in the Harz Mountains.  The report describes the flowers growing from rotten twigs lying on the ground as ". . . ice-excrescences of soft, brilliant, asbestine appearance, and uncommonly delicate to the touch. . . . Prof. Schwalbe brought some of these withered and rotten twigs with him to Berlin, and it was in his power to produce on them at any time the phenomenon just described.  For this purpose all that was needed was thoroughly to moisten the twig, in such a manner, however, that no water dropped off, and then to let it cool slowly in a cold preparation.  Ice-excrescences also appeared of themselves on twigs lying in the garden whenever the temperature fell below 0 degree C. in the night."  (p. 472) 

In a later editions of Nature there were a series of letters reporting on ice formations and reacting to earlier letters.  Most of these reports relate to what was obviously needle ice but in the January 1, 1885 issue B. Woodd Smith tells of a friend who “. . . picked up a  piece of a dead beech-branch which was covered with filamentous ice, such as is described by the Duke of Argyll and others.”  This person found the ice reappeared again the next morning when it was left out over night.  (p. 194). 

So, this is far from a new phenomenon.  In spring 2007 I received an email from Joachim Mittendorf in Sweden with a photo of a similar occurrence of ice on wood he saw in the Harz Mountains of Germany, where Prof. Schwalbe saw ice more than a century earlier. 

Mittendorf took a very clear photo.  The leaves look like Beech.  Note that there is no ice where there is bark.  Hillenfors, 1976, made that same observation. 

And, someone put me on to two photos of such ice formations on the Geograph web site in the UK where the goal is to have photos of every grid square.  The links to these photos are and

These two photos are from near Inverness, Scotland.  There is no doubt these photos are showing the same type of ice seen in Wales, Germany and the Olympic Peninsula.  I suspect there will be many more examples out there on cold mornings in late fall and early winter around the world.  Go for it, but be aware that they are ephemeral and are likely to be gone before noon.

As spring 2008 approached I received a gold mine on this type of ice formation.  Gerhard Wagner and Alfred Weiersmiller of Switzerland pointed me to web pages showing many views of such formations and to articles by Wagner.  Der Karlsruher Wolkenatlas has five photos of Haareis, the common name for this in German.  The Natur Galerie von Paul Esser has a nice collection of photos, #2 of which is Haareis. It is my interpretation that the ice in this photo is not as long as in many photos, but in this example the wood seems to stand vertical and may be part of a living tree.  The web site has two photos of Haareis on pieces of wood on the ground.  In these two photos the threads of ice are quite long, especially compared to the Natur Galerie photo.  And, here the piece of wood is horizontal on the ground and as such it should have access to drawing water up from the underlying soil. 

Gerhart Wagner has published two articles on Haareis and is currently conducting experiments on these ice formations.  He is finding a relationship between the formation of Haareis and the presence of a fungus.  His articles are available for download as pdf files from   and    

Then I received a photo from the Netherlands showing a good example of Haareis.  So, another country in Europe is home to these ice formations.  Interestingly, a few weeks before I had received photos of Ice Flowers from the Netherlands.  Those are the first examples of Ice Flowers I have seen in Europe.

All of these occurrences of Haareis, or ice on wood, have been on Beech or at least everyone assumes it is Beech.  But, then I received an email from a person on Vancouver Island, British Columbia, who reported seeing such ice on Red Alder and possibly Big Leaf Maple.  Ah, yes, there is much we have to learn.

Thank goodness for the Internet and digital cameras for they let us exchange information about these attractive ice formations.  Feel free to contact me at  if you see any ice of this nature in your early morning outings.



One of the many web pages of Dr. Jim Carter