Need to plough garden (4)
I believe the answer is:
eden
'garden' is the definition.
(Garden of Eden in the Bible)
'need to plough' is the wordplay.
'to plough' indicates anagramming the letters (I've seen 'ploughing' mean this (to plough is to break up or disrupt)).
'need' with letters rearranged gives 'EDEN'.
(Other definitions for eden that I've seen before include "Perfect place" , "project in the south west" , "A Conservative PM" , "In need of a great garden" , "Early garden - Cornish project" .)