This circular clock has been planted out since 1903 with up to 40,000 plants in an ornate design reflecting a different theme each summer.
The idea came from James McHattie, City Superintendent of Parks and James Ritchie, the Edinburgh clockmaker, using the mechanism of a redundant turret clock.
In 1905 a cuckoo which pops out every hour was added, and in 1934 a new mechanism was installed by Ritchie and Sons, who still service it.
In the clock's centenary year (2003), it won a Gold medal at the Chelsea Flower Show.
As you can see there was still a person working on the planting when we passed by.