Fences of bushes (6)
I believe the answer is:
hedges
'fences of bushes' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for hedges that I've seen before include "Fences of bushes" , "Boundaries of low woody plants" , "Fences made for business" , "guards" , "Buys or sells protective security" .)