We used to book all sorts of acts for the folk club we ran in Yeovil from 1963 - 1967. One such was a family group called the McPeakes. They came from Belfast and always included 'The Wild Mountain Thyme' in their show. Soon the song spread around the country and a lot of clubs rounded off the night with it We frequently still do at our Music Nights in Sherbome.
Rod Stewart adapted it for the Scottish National Football Team in 1996 to aid their bid for the European Cup. Sad to say, it didn't help them very much.