Need to transform the original garden (4)
I believe the answer is:
eden
'original garden' is the definition.
(I've seen this in another clue)
'need to transform' is the wordplay.
'to transform' indicates an anagram.
'need' is an anagram of 'EDEN'.
'the' acts as a link.
(Other definitions for eden that I've seen before include "Unspoiled paradise" , "prime minister in the past" , "Adam and Eve's 19" , "(Biblical) paradise" , "Adam and Eve's garden" .)