How do you breed a blue fire dragon in DragonVale?

The most effective method is Fire (lvl 10) + Ice (lvl 10). This has a success rate of about 17%. It will take 12 hours to breed and another 12 hours to hatch. The egg will be red with white snowflakes. You must be a minimum of a level 4.

Some other options are:

• Fire (lvl 10) + Snow (lvl 10) = 15% chance
• Fire (lvl 10) + Storm (lvl 10) = 12% chance