Glow-in-the-Dark Plants Are Real. Here’s how to enjoy them in your yard.
It may sound like science fiction, but you can enjoy glow-in-the-dark plants in your garden. A company called Light.Bio has been working on the idea since the 1980s and in 2025 they’re making their first variety—a Petunia called Firefly—readily available.
How it Works
Firefly Petunia was brought to life by inserting genes from a bioluminescent tropical mushroom into a Petunia. The result is a plant that looks like your average, everyday white-flowering Petunia during the day. But then after the sun goes down, you can see a soft greenish glow (reminiscent of fireflies) cast mainly from the flower buds and flowers.
After the petunia was developed, it was rigorously tested by the USDA and APHIS (Animal and Plant Health Inspection Service) to ensure it didn’t pose a risk to pollinators, wildlife, or native plants in the area.
How to Grow Firefly Petunia
Despite its fascinating glow-in-the-dark nature, Firefly Petunia grows just like any other variety. So give it a spot with full sun or part shade (at least 8 hours of direct sun is ideal). Water as the soil starts to dry out—the amount and frequency of water you need to use will vary based on your growing conditions. But Firefly Petunia isn’t particularly drought tolerant.
It grows best when conditions are between about 65 and 80F; excessively warmer temperatures, particularly at night, can lead to a little stress. It’s best to protect it from frost; freezing temperatures can kill the plant.
If you’re growing it in the landscape, a moist, well-draining soil rich in organic matter is best. Amend heavy clay liberally with organic matter for best results. If you’re growing Firefly Petunia in containers, any quality potting mix made for pots and planters should be sufficient.
Like other Petunias, Firefly is considered a heavy feeder, so regular fertilization can help keep it blooming profusely and glowing best.
Enjoying the Glow
The darker it is at night, the more you’ll see the glow from your Firefly Petunia. If there are streetlights or other ambient light sources nearby, it can reduce the amount of glow you perceive. Likewise, you’ll notice the glow more on clear, moonless lights than on nights when there’s a bright full moon. In urban and suburban areas with lots of light pollution, you’ll detect less of a glow.
If you want to grow Firefly Petunia, pick a spot where you’ll be able to enjoy it at night. That may take a little bit of a mindshift. For example, if you usually plant flowers by your front door because you pass by every day coming to and from work, you may rarely get to enjoy the blooms if you get home before dark and close the curtains as it gets dark outside.
It might be perfect for planters on your deck or patio if that’s a place you hang out after the sun goes down. Or it might be in a window box so you can see it up close just outside a window of your bedroom. From a landscape perspective, Firefly Petunia can be both fun and functional along pathways, for example, to help with wayfinding in the dark.
From a design perspective, consider pairing it with other white flowers or silver foliage. Light colors like that help pick up and reflect the glow a little, adding to the overall display at night.
All articles are copyrighted and remain the property of the author.
Tight on space? Go vertical! And your neighbors will thank you too. Click here for an interesting article with great ideas for planting vigorous Sun Parasol Giant mandevillas.
Click here to sign up for our monthly NEWSLETTER packed with great articles and helpful tips for your home, garden and pets!
