Knowledge initially transformed the Garden of England (4)
I believe the answer is:
kent
'garden of england' is the definition.
(I've seen this before)
'knowledge initially transformed' is the wordplay.
'knowledge' becomes 'ken' (ken is a kind of knowledge).
'initially' says to take the initial letters.
The first letter of 'transformed' is 't'.
'ken'+'t'='KENT'
'the' acts as a link.
(Other definitions for kent that I've seen before include "South-eastern county" , "County of SE England" , "Earl Lear banishes" , "Home county" , "County; punting pole" .)