A basic setup involves a wooden pole, a copper spiral winding upward, and a grounding spike or buried wire

https://kameronotff660.theburnward.com/electro-culture-gardening-optimizing-growth-cycles-with-currents

A basic setup involves a wooden pole, a copper spiral winding upward, and a grounding spike or buried wire, positioned near crops to capture atmospheric ions and gently influence local electrostatic conditions.