Rose coming up in flower garden (4)
I believe the answer is:
grew
'rose' is the definition.
(I've seen this before)
'up in flower garden' is the wordplay.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'in' says the answer is hidden in the clue.
'werg' is hidden within 'flower garden'.
'werg' in reverse letter order is 'GREW'.
'coming' is the link.
(Other definitions for grew that I've seen before include "Multiplied" , "Sprouted" , "Developed, matured" , "Expanded - flourished" , "Rose" .)