Can Plants Grow Gold? The Strange Science of Phytoextraction

From Fertilizer to Gold — The Legacy of Fritz Haber

Hydroponics may seem a world away from mining, but the two are more connected than you’d think. In today’s blog we explore the fascinating story of Fritz Haber, the man behind the Haber-Bosch process—a method that revolutionized nitrogen fertilizer and helped feed billions.

But Haber’s ambitions didn’t stop at saving lives. He once claimed he could extract gold from seawater, convincing the German government to agree to harsh World War I reparations based on this promise. The only problem? His math was wildly off.

You could extract gold from seawater but not economically.

Enter Hyperaccumulator Plants: The Natural Gold Collectors

While Haber’s seawater gold dream failed, nature had its own ideas. Certain plants—called hyperaccumulators—have evolved the ability to absorb high levels of metals from the soil.

To qualify as a hyperaccumulator, a plant must:

• Absorb 1 to 10 grams of a metal per kilogram of dry biomass.
• Tolerate and store toxic metals in stems and leaves.
• Thrive in metal-rich or contaminated soils.

These plants don’t just pull in gold—they can accumulate nickel, copper, chromium, and even uranium.

Why Do Plants Absorb Metals?

Scientists believe hyperaccumulation evolved for two key reasons:

1. Defense – The toxic metals deter herbivores.
2. Detoxification – Moving metals out of the root zone protects essential functions.

In some species, the build-up of gold or heavy metals in leaves is a side effect of survival in harsh, nutrient-poor environments.

Gold-Accumulating Plants: Who Are the Champions?

Here are a few known gold-loving species:

These species have shown uptake of gold ranging from 1 to 60 micrograms per gram, depending on soil conditions and enhancement techniques.

Enhancing Gold Uptake with Chemistry

Researchers found that gold uptake can be boosted by adding ammonium thiocyanate—a chemical used in mining to dissolve metals. With the right combination of:

• Soil chemistry
• Chelating agents
• pH and nutrient control

…the concentration of gold in plants can be pushed higher—especially in controlled systems like hydroponics.

Phytoextraction Meets Hydroponics: A Future for Sustainable Mining?

Hydroponics may not mine gold tomorrow—but it could play a role in the future of eco-friendly resource recovery.

Here’s how:

✅ Hydroponics offers:

• Precision nutrient delivery
• Tightly controlled root zones
• Minimal soil disturbance
• Scalable systems for lab research

It could even be used for cleaning up mining runoff, such as mercury-contaminated water in gold mining areas.

Burn, Harvest, Extract: Turning Biomass into Metal

Once a hyperaccumulating plant absorbs metals:

1. It’s harvested and dried.
2. The biomass is burned, leaving a mineral-rich ash.
3. The metal is chemically extracted from the ash.

This process—known as phytomining—could one day offer a low-impact alternative to open-pit mining, especially for rare metals used in:

• Batteries
• Electronics
• Green energy systems

Botany, Mining & Ethics: Strange Bedfellows

It turns out botanists and geologists often play a key role in mining. Some companies use plant-based indicators to discover new mineral deposits.

Botanists are sent into wild regions—like Canada or Australia—to identify plants with unusual metal levels. This data helps geologists locate new sources of uranium, gold, and rare earth elements.

So yes, your botany degree might land you in a mining company.

Real-World Research: The UK’s Phyto-Mining Startups

Fiona, a UK-based spinout from Brunel University, currently researching plant-based gold and nickel extraction. While still in early stages, their work could pave the way for real-world applications.

Conclusion: Growing Gold Is Still a Dream—But Not a Fantasy

We’re not planting gold bars in the garden yet, but the science is real, and the possibilities are fascinating. Whether it’s cleaning toxic soil, recovering valuable metals, or exploring sustainable mining, plants may hold more power than we realize.

Article by Dr Russell Sharp

If you would like to keep up to date with subjects just like this, you can listen to both our podcasts! Links can be found bellow:

Hydroponics Daily Podcast: https://open.spotify.com/show/207T7p7fw9sPjINfSjVXW2

Cereal Killers Podcast: https://t.co/eSEbBkTVHl