Sometime part of Treleigh Wood. Wheal Garden was established around 1816-1817 through the amalgamation of Treleigh Wood Mine with several smaller mines in the vicinity. These included Wheal Diamond, Wheal Butler copper mine, and Wheal Gilbert. Initially, these mines operated using water-driven engines and did not delve deep into the ground. However, plans were devised to introduce steam engines and dig a deep adit to explore numerous unexploited lodes.

After obtaining the lease, the mine was renamed Wheal Harmony. According to Dines, Wheal Harmony focused on exploiting the eastern extension of the Wheal Tolgus main lode. Despite the absence of mine plans, there are indications that the mine followed this lode for approximately 600 yards to the east.