For balcony growers, compact coil pots use a small copper helix inserted into the medium

https://blogfreely.net/galenacmeo/case-studies-in-electroculture-real-garden-results-and-lessons-learned-qml2

For balcony growers, compact coil pots use a small copper helix inserted into the medium, aiming to localize subtle charges near roots without requiring tall poles or complex grounding arrangements.