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

https://blogfreely.net/galenacmeo/electroculture-for-heirloom-vegetables-preserving-flavor-while-boosting-growth

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.