Flowers are already beautiful, but have you ever wanted to make glowing flowers so you could see them in the dark? All you need is a bit of basic chemistry and biology to make real flowers glow. Here are four methods to make glowing flowers. There are instructions for both fluorescent flowers (glow under a black light) and phosphorescent flowers (really glow in the dark). There are no naturally bioluminescent flowers, but genetic engineering can make plants glow that way, too.
Did You Know: Chlorophyll in living plants glows red. This fluorescence is too dim for human eyes to see, but NASA scientists make global maps to assess ecosystem health.
Glowing Flowers With Highlighter Ink
Customize the color of glowing flowers using fluorescent highlighter ink. This project is fun for kids of all ages. You’ll need a black light to see the glow.
- Turn on the black light and test the highlighters to make sure they glow. Yellow and green almost always glow, but orange, blue, and red require testing.
- Use pliers or tweezers to pull the ink pad out of the marker. Other options include whacking the pen with a hammer or cutting it open with a knife, but the felt pad usually comes out fine without the drama.
- You can squeeze the ink out of the pad into a vase containing some water or simply drop the ink stick into the vase of water and let diffusion do the work for you.
- Trim the end of the flower so it can absorb water. If you can, snip it with scissors while the stem is in the water so it won’t get air bubbles.
- Allow a few hours for the water to absorb the fluorescent ink.
- Turn on the black light and appreciate your work. (Really, it’s fun to have the black light on the whole time to watch the progress.)
Make Flowers Glow With Tonic Water
Tonic water contains quinine, which glows bright blue under a black light. While you can’t change the color of the glow, the liquid is safe to drink and won’t stain your fingers. Tonic water works best with white flowers. Either regular or diet tonic water works, but the flowers will appreciate the sugar in the normal soda.
- Pour tonic water into a vase.
- Cut the end of the flower stem so it can absorb water. Again, this works best if you snip the stem under water so the cut end doesn’t get blocked by air bubbles.
- Allow several hours for the quinine to make its way to the edges of the flower petals.
- Turn on the black light and enjoy the display.
Make Flowers Glow With the Dip Method
Some flowers don’t drink a lot of water, so it’s hard to make them glow by adding dye to a vase. Woody flowers like roses fall into this category. Make these flowers glow by immersing the flower head in the dye. You can use fluorescent highlighter ink or tonic water (black light needed/petals absorb the glow) or any glow in the dark paint (no black light needed/petals coated with glow).
- Prepare a container of highlighter ink in water or tonic water. Alternatively, dilute glow paint or glue in water to thin it out. Make sure the container is big enough for the flower head.
- Wrap a damp paper towel around the cut end of the flower to give it water and keep it healthy.
- Invert the flower into the liquid. Swish it around to dislodge air bubbles.
- For best results, let the flower soak up the color for an hour or two.
- Remove the flower from the liquid and place it in a vase with water. Expose the flower to bright light before turning out the lights to enjoy the glow.
Glowing Flowers Without a Black Light
Flowers glow in the dark without a black light by a process called phosphorescence. In phosphorescence, a material absorbs light and then slowly releases it over time. Some phosphorescent materials glow for hours or even days.
Obtain phosphorescent powder. This is available online. Green and blue glow longer and more brightly than white, yellow, red, or purple. Larger particles glow better than smaller ones. Which size you choose depends on the desired effect. Fine particles result in an all-over glow. Large particles produce glowing spots.
Plants won’t absorb these large particles, so you have to apply them to the flower surface. You can mix fine powder with water and spritz it onto flowers. This dries to a fine dust that glows in the dark. Another option is to spray the flowers with a craft adhesive and then dip them into the glow powder. This works great for larger particles, plus the “glow” won’t fall off the flowers.
Tips for Best Results
- Choose fresh, healthy flowers. Carnation and daisies work well. Plant health is especially important if you put dye in the water because dead flowers won’t take up liquid.
- White or pale flowers work best at absorbing dye. Dense pigments can block the glow. If the surface of the flower is coated, you can use darker flowers. But, pale flowers reflect more light and enhance the glow!
- Joiner, J.; Yoshida, A.; Vasilkov, P.; Yoshida, Y.; Corp, L. A.; Middleton, E. M. (2011). “First observations of global and seasonal terrestrial chlorophyll fluorescence from space”. Biogeosciences. 8, 637-651.
- NASA Earth Observatory. “Measuring Plant Health From Fluorescent Light.”