No citrus flavour before with balsam? Leave well alone! (4,2,7)
I believe the answer is:
noli me tangere
'leave well alone' is the definition.
(Latin for 'touch me not')
'no citrus flavour before' is the wordplay.
'citrus' becomes 'lime' (lime is a kind of citrus).
'flavour' becomes 'tang' ('tang' can be a synonym of 'flavour').
'before' becomes 'ere' (usually literary).
'no'+'lime'+'tang'+'ere'='NOLI-ME-TANGERE'
'with balsam?' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
(Another definition for noli me tangere that I've seen is " plant".)