Today’s entry on fairy ring fungus was kindly submitted and written by UBC Botanical Garden’s director, Dr. Quentin Cronk – Daniel.
These fairy rings from central London are taken from Google Earth™ (latitude: 51 degrees 30′ 28.13″ North; longitude: 0 degrees 11′ 22.41″ West). They are in the extreme north west section of Kensington Gardens (a section not open to the public), just north of Kensington Palace. The fairy rings are marked by a dark green growth of grass, caused by the advancing hyphal front releasing nutrients and stimulating the growth of the grass. Inside this is usually a zone of poor grass growth caused by the available nutrients being taken up by the fungus. Further towards the centre of the ring the grass growth becomes better again as the old hyphae die and nutrients are released. There are several fungi that cause fairy rings, but these ones in Kensington gardens are most probably caused by Marasmius oreades, which is one of the commonest lawn fairy rings of this type in Britain. The largest of these fairy rings in Kensington Gardens appear to be 10-15 metres across and as fairy rings grow at about 10-20 cm per year, they may be over 100 years old. Certainly they are likely to date from after 1841 when the western part of the Kensington Palace estate was remodelled to develop the exclusive neighbourhood of Kensington Palace Gardens (just to the left of this picture).
Fairy ring growth is a curious process and has been the subject of many studies (including mathematical modelling). Usually when two rings meet they extinguish each other, as they cannot grow through each other’s zone of depletion. However, in this photograph it can be seen that several of the rings have successfully crossed.
In folklore they were thought to be the work of fairies or elves and hence Prospero (in Shakespeare’s Tempest) exclaims: “you demi-puppets that by moonshine do the green sour ringlets make”. Many gardeners try to get rid of the rings as they consider them unsightly. However, be warned! According to mycologist Gordon Rutter writing in the Fortean Times, fairy mischief may wreak havoc on the unwary who disturb the rings. It may be best to leave them well alone, as at Kensington Gardens.
And a few extra links on Marasmius oreades: Tom Volk’s Fungus of the Month and Michael Kuo’s MushroomExpert – Daniel.

fascinating photo and commentary; thanks!
I echo Bev’s comment. Most educational. Thanks.
This is amazing. I love this site.
Wow, and here I thought these were just fiction. What a wonderful world of plants that we live in.
I had no idea that fairy rings could be so established and so old. So one can get a rough idea of the age by looking at a ring’s size. History through fungi.
Those are either very tiny fairy rings or that is a very large push pin.
Carol, it’s a large push pin. I’m actually underneath it holding it up, but you can’t see me because of the oblique angle – that should give you a sense of scale, though.
I’m an avid follower of this site and look forward to each picture with anticipation. In this case, it’s difficult for me get a sense of scale – if this is an arial photograph, which I believe it is, then a bigger object should been put next to it like a car or a cut out of one. The push pin only confuses the viewer and your answer to Carol confuses me even more.
In my hikes I’ve seen ring mycena appear in various forests I’ve visited (mostly in Ontario). It takes a keen eye to realize that you are looking at a ring. As your article indicates the size of the ring varies with age.
Hello Aida, yes, the image is lacking an effective sense of scale, but Quentin did provide an estimate of size in his write-up.
The lower left corner provides the only hint – I believe that’s a two lane access road with two tall sheds on the pull-off, likely where the grounds maintenance equipment is stored. Unfortunately, I found zooming out to get a larger perspective tended to make the rings appear more as blotches and lose detail.
I assumed that Carol’s push pin comment was a subtle joke, and I replied in kind.
This is really neat. Its a amazing what can be learned when driving on the information super highway.
I enjoyed this photo and the comments. I discovered an unusual pair of “fairy rings” in my yard this week. They were in the unmistakable form of the symbols of infinity and zero. I will be happy to forward a photo series showing this phenomenom.
WE have fairy rings on our lawn. I pick them dry them and use them in cooking. In Australia it is hard to find out wich fungi is edible.
Can anyone tell me how to get rid of a pronounced fairy ring
in my lawn? I find it unsightly. Should I try to dig it out and re-turf that section? Or will it come back?
What’s really interesting is that each ring is a single organism.
My father, Simon Stuart, published a poem in the 1960s. It starts with him standing outside the Orangery in Kensington Palace Gardens, reflecting on the mathematical symmetries in nature, replicated in the artificial symmetries in, for example, the landscape artist Bridgman’s formal topiary in the Gardens. Here’s a few lines from the poem:
And here below, where Bridgman set
The hollies, mycelial strands beget
Marasmius oreades, seen
In perfect circles on the green…
Decurrent gills, on looking closer,
Of Clitocybe rivulosa.