CHAPTER TWENTY

The Copper Coil on Trial

We come now to the thing most readers picked up this book to learn about: the copper wire wound on a wooden stake.

What is claimed

The modern electroculture antenna is usually a wooden dowel or branch a few feet long, wound from bottom to top with bare copper wire, sometimes with a coil or spiral at the tip, pushed into the soil of a bed or pot. Variants include free-standing spirals, copper rings around the stem after Lakhovsky, pyramids, and coils wound to particular proportions. Instructions often specify winding clockwise in the northern hemisphere and aligning to magnetic north.

It is claimed to raise yields greatly, speed growth, reduce pests and disease, and cut the need for water and fertilizer.

What the evidence is

I have searched for controlled, replicated, peer-reviewed trials showing that a passive copper antenna improves plant growth. I have not found one.

The evidence offered consists of testimonials and before-and-after or side-by-side photographs. Where gardening educators and extension writers have run their own simple side-by-side comparisons, the ones I have seen report no difference. I should be exact about the limits of that statement: informal tests are not rigorous either, and the absence of a published positive trial is not the same as a published negative one. This is a cheap experiment that agricultural science has mostly not bothered to do.

But three bodies of evidence do bear on it. The history: the unpowered wire was tried by many people at once in 1845 and failed. The physics: as an earlier chapter showed, there is almost no energy for such a device to deliver. And the pattern of the claims themselves, which grow larger the less measurement is involved.

Why honest people see results

Most people who report success with a coil are not lying. They saw what they saw. The question is what caused it. There are several well-understood answers.

• No real comparison. “My tomatoes did better than last year” compares different weather, different seed and a more experienced gardener. One plant with a coil beside one without is a sample of one; any two plants differ.
• Placement. People put the new device on the plant or bed they care most about, which tends to be the one in the best spot.
• Attention. A gardener trying something new visits that bed more, waters it more faithfully, weeds it, notices problems sooner. Ingenhousz identified this in the 1780s.
• The winners post. A person whose coiled plant thrived makes a video. A person whose coiled plant did nothing does not. Viewers see only one side.
• Copper itself. Bare copper in damp soil slowly releases copper ions. Copper is a necessary plant micronutrient, a long-established fungicide, and reputed to deter slugs. In a soil short of copper, or a bed troubled by fungus, a length of copper wire could do some real good by chemistry alone, and a piece of copper scrap would do the same. In excess, copper is toxic to plants and soil life.

None of these requires the antenna to collect anything from the sky.

The galvanic case

The buried copper-and-zinc pair is a different matter and should not be dismissed with the coil. Here a real current does flow, and you can measure it with an inexpensive meter. Whether that current does a plant any good has, as far as I can find, not been properly tested in modern times. The metals also dissolve, zinc especially, and zinc too is a micronutrient, so any trial must include buried but unconnected plates as its control. The honest status of galvanic electroculture is: real current, unknown effect.