Dark Plants as Alternatives to Street Lights? Not a Chance!

There are some product ideas that elicit just a sigh, while others I genuinely dislike. The fluorescent plants created by injecting leaves with glowing substances definitely fall into the latter category for me.

These plants are developed by researchers at the Agricultural University of South China. Recent research indicates that these plants exhibit “extraordinary brightness” and represent a move towards a “sustainable and environmentally friendly plant-based lighting solution.”

The quest to create glowing plants has spanned decades. A notable challenge is intensifying their glow for visibility. A Kickstarter project in 2013 amassed nearly $500,000 but ultimately failed to deliver on its promises.

Last year, US biotech firm Light Bio introduced the Firefly Petunia, the first genetically modified plant available for retail. They claim the plants shine “like moonlight”, but judging by social media images, it seems we’re far from a full moon effect.

The difficulty in producing glowing plants stems from plants deriving energy from light, but photosynthesis is notoriously inefficient. Estimates suggest most plants capture under 2% of the light that strikes them, and much of that energy is used for growth, leaving little to emit light.

This limitation means that energy captured from photosynthesis can never produce a plant bright enough to replace street lights. This inefficiency likely explains why most animals harness energy from plants rather than growing under the burden of photosynthesis (and also why placing solar panels on farmland promotes crop transformation into biofuels).

Consequently, several research groups have attempted to integrate sustained phosphors directly into mature plants. These compounds mimic the glow of stars in the night sky and can emit light after being charged.

Certain sustained phosphors can be significantly more efficient than photosynthesis, letting more light escape from an equal input. However, even distribution within the leaves poses challenges. Recently, Chinese researchers discovered that this kind of distribution could be more easily achieved in succulents like Echeveria “Mebina,” enabling vibrant fluorescent plants of various hues through manual injection of phosphors into each leaf.

This approach feels like a superficial gimmick. I won’t deny my interest in genuinely glowing plants. While you can find the Firefly Petunia available outside the US, I view giving plants a shine through direct injection of glowing substances as a shortcut. At the very least, this glow fades as the plants mature. There’s also a concern about possible contamination when these plants are disposed of.

While this practice may not be as unethical as dyeing aquarium fish, it’s certainly less appealing than dyeing roses. (And no, I’m not having an Alice in Wonderland moment—painted roses do exist.) Furthermore, the team’s paper does not address the environmental or safety implications of plants containing elevated levels of phosphor. I reached out to the researchers for clarification but had yet to receive a response at the time of writing.

If scientists could genetically engineer plants to produce their own biodegradable phosphors that last, this could turn into an entirely different scenario. This capability could even enhance photosynthesis efficiency. Allowing plants to temporarily “store” light would help mitigate fluctuations in light levels, converting unusable wavelengths into usable ones, thereby maintaining photosynthesis into the night. One day, entire fields might illuminate the darkness.

For now, I don’t wish to see a synthetic glowing plant derived from phosphor injections hit store shelves. I hope that never happens, yet I worry there’s a chance it might.