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

https://andersonvngw461.tearosediner.net/maximizing-tomato-yields-with-electroculture-techniques

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.