Hedge Witch is a bit difficult to define because what the term meant originally and what it means today is nowhere close to the same thing. To make matters more confusing, people who accept each meaning of the term currently practice and call themselves Hedge Witches. There are people who adhere to one meaning or the other and people who meld both practices together.
Which sort of made it like a prison as well.
Outside the hedge was the unknown. Dangerous animals roamed about. The outcasts lived beyond the hedge. All of the wild, untamed things that makes nature frightening was outside the hedge.
Which gave it absolute freedom.
The Witch needed to live outside the hedge so she could have access to plants not grown in the village. She needed the privacy to work her magick. And you could be certain that if anyone was brave enough to find her then they surely had a real need otherwise they wouldn't have trekked through uncertain territory to find her. The second meaning of Hedge Witch involves the spells she performed.
Hedge Witch is often called Hedge Rider. This refers to the person who walks between the worlds, the person who communicated with the dead, the gods, or the animals. All of which would have been re-enforced in the villager's mind as they fearfully walked through the dark forest to see the Witch.
The hedge is a between place. It separates the village from the wild, it had to be planted so it is not wild, yet people couldn't cross it. Hedges are filled with birds and other small animals. You can never completely see into a hedge. Something thrown into a hedge is probably lost forever.
There are people now who think of Hedge Witchery as being like Kitchen Witchery. Or they think of it as a form of 'green' Witchcraft (I'll talk about this more in a later post).
I think Hedge Witch is the Witch who can cross any boundary she chooses. She's not limited by time or space or rules of society. And I think that's the real reason she was so feared. Nothing could contain her.