You may be familiar with the saga of the ornamental stone urn on the right hand pillar at the park’s main entrance. After standing there for 80 years, in 2013 it was knocked off and smashed by a contractor’s vehicle. Last summer, a replacement was created and put in place but it is much more yellow then its left hand counterpart. The Friends of Braidburn Valley Park came up with ‘Project Yoghurt’ to speed up the natural colonisation process and even up the colours.

Painting a thin layer of diluted yoghurt on stone acts as a spawning ground for bacteria and fungi – the initial biological colonisers. However, they have a hard time getting started when the stone is sterile. The yoghurt layer gets them going, then green algae come along, then lichen. The Friends were delighted that Waitrose in Morningside were able to help by donating 5 litres of natural, low fat yoghurt (although we would have been happy with any flavour!). At the end of July, we got out the long ladders and painted and squirted the yoghurt on the urn to make sure that it was completely covered.

Painting yoghurt on the stone urn

Historic Scotland advises that it will take at least six months before we see any lichens or algae starting to grow. Initially they will be tiny millimetre diameter pinheads. They will only growa millimetre or so a year even with the help of the yoghurt, with lichens probably appearing on the sunlit (drier) side and green algae on the shaded (damper) side.

The Friends ask our regular park users to keep an eye on the right hand urn and when you are next eating yoghurt, think of its more unusual uses!