You can make flowers that glow in the dark under ultraviolet light using a fluorescent dye. All you really need are two things, an ultraviolet lamp and a fluorescent highlighter. Open the highlighter and squeeze a few drops of the fluorescent ink into a cup of water. Now take the flower (white carnations work the best) and cut the stem underneath the solution. Leave the flower in overnight and the dye will have been absorbed into the flower. Now simply shine an ultraviolet light onto the flower to cause the highlighter dye to glow.
Make Flowers Glow In The Dark
Video by NurdRage