One can isolate fire by puting flowers around it or near it if one does not wish it to go in that direction. Grass and leaves burn, shouldn't flowers?

EDIT: Can confirm what Alex Collins said in the latest version, dead bushes and saplings (that can be used as fuel in the furnace) alongside flowers do not burn. It is impossible to create forest fires because of this. Sure some trees will burn but no one is in any real danger. Don't know if this is intentional or not.