Fire is a very hard tool to work with with timing and light. Flowers are very hard to burn but maybe next time try to use a fake flower. Fake flowers have a fabric, which burns much more easily and burns slower so you have time to take a few shots with it.
As for this piece, it was a great attempt. However, while working with fire you need to have just a little more depth with your lighting. Try to shoot in a darker area. If you plan to shoot outside, do it RIGHT when the sun does down in a darker forest area and underexpose your image on purpose so that the fire can really pop.
If you plan to shoot indoor, close all the windows and light sources. Under expose you image by just a little, and you will find that your fire will really really pop!