Some grass to spare perhaps (7)
I believe the answer is:
esparto
'some grass' is the definition.
(type of grass plant)
'to spare perhaps' is the wordplay.
'perhaps' indicates an anagram.
'to'+'spare'='tospare'
'tospare' with letters rearranged gives 'ESPARTO'.
(Other definitions for esparto that I've seen before include "Grass fibre for mat-making" , "Grass, used for ropes, paper" , "Rope-making process" , "Tap Eros for the grass" , "Coarse type of grass" .)