A writer's turf (5)
I believe the answer is:
grass
I believe this clue is a double definition.
'a writer's' is the first definition.
(German novelist Gunter Grass)
'turf' is the second definition.
(I've seen this before)
(Other definitions for grass that I've seen before include "Common plant" , "Lawn - informer" , "Weed" , "Drug" , "Pasture" .)