@Bushman501 It would work, I could heal it after, but the mouth and wings will injure it further if it struggles, and the problem about collapsing trees is that a stray branch could impale the dragon and accidentally kill it, I'm not sure however if the scales of this dragon is like that of Smaug, like iron that won't let anything through or if they were like the dragons from animations and stuff that would die from arrow shot and swords.
I would like to propose perhaps an explosion that would knock him out but not kill him, like a concussion, minimal damage, no bleeding, no struggle.