Refuse hidden in the garden, you know (4)
I believe the answer is:
deny
'refuse' is the definition.
(I know that refuse can be written as deny)
'hidden in the garden you know' is the wordplay.
'hidden in' indicates a hidden word.
'DENY' can be found hidden inside 'garden you know'.
(Other definitions for deny that I've seen before include "Forbid; contradict" , "Refuse to give" , "contest" , "Claim to be untrue" , "Forbid; not agree" .)