Foliage goes away (6)
I believe the answer is:
leaves
This clue is a double definition.
'foliage' is the first definition.
(I've seen this in another clue)
'goes away' is the second definition.
(leaving is a kind of going away)
(Other definitions for leaves that I've seen before include "See 14" , "Steps out of" , "Disappears" , "''... of Grass'' (Walt Whitman)" , "They are found on trees and in books" .)