Refuse to go to seed (7)
I believe the answer is:
decline
I believe this clue is a double definition.
'refuse' is the first definition.
(I know that refuse can be written as decline)
'go to seed' is the second definition.
(to go to seed is to decline or deteriorate)
'to' acts as a link.
(Other definitions for decline that I've seen before include "Lessen" , "Downturn - turn down" , "The Latin scholar must" , "The classics student must often" , "go through cases" .)