Thanks to all of you for the nice comments!

Wireman- Someone suggested to me to kill the fireflies when they are glowing this causes the glowing to stay. then pick a cottonswab press the glowing tail and then put the glowing liquid in the plant. I have attemped this with a sarra, but i only found one firefly, so it doesn't look great(now, collect some 50 fireflies, and collect all the liquid fast, then paint your CP with it ). I had to use scissors to cut the tail fast, not fun to do, then the glowing liquid is all nasty, but here's a pic: