Usage patterns
野に咲く〈物〉a flower/plant that blooms out in the fields
I found a flower blooming in the field and picked it.
〈動物〉を野に放つto release an animal into the wild
They released the bird they had been caring for back into the wild.
〈人〉が野に下るfor someone to leave an official/political post and return to private life
He lost the election and returned to private life.
Expressions
虎を野に放つlet loose a tiger in the field; unleash something dangerous 野となれ山となれI don't care what happens after this; come what may 後は野となれ山となれI don't care what happens next; the future will take care of itself