Never having come across this anywhere else on my travels, I can't quite tell how this was achieved ?

Is there a technique to creating geometric symmetry with something as wild as moss ?

I'm assuming the design is not carved into the wall caps...the surface is smooth?

This article describes how to create a moss slurry and paint it on to concrete to grow moss. The section about making designs is down a ways. I would think the UK would be a most hospitable climate for these creations. Very cool!

If this is how your example was created, looks like it took some effort and time!

Warning, this site is annoyingly ad-heavy
https://plantophiles.com/garde...

Interesting.

I may well ask the home owner..

makes me want to know what other interesting finds are in that garden!

I found out the reason why : a random act of kindness.

The house owner said that they didn't know why it happened but assumed it to be children as one day it just appeared.




On closer inspection I think the grinding pattern can be made out to which this crop-circle like mystery can be put to rest.

@Frillylily : to pique your curiosity:

That's the best answer to the question ever! Thanks for getting back to us on that, Aleema.

I even checked back on Google Maps to see if the vagabond(s) had struck in previous years, but it was no the case.

However, the wall grew in height by one third shortly after the financial crisis, gaining its granite capstones three years after.