... take out of production and harden fresh ideas (3,5)
I believe the answer is:
set aside
'take out of production' is the definition.
(to set something aside is to take it out)
'harden fresh ideas' is the wordplay.
'harden' becomes 'set' (set can mean to go hard or dry).
'fresh' indicates anagramming the letters.
'ideas' with letters rearranged gives 'aside'.
'set'+'aside'='SET-ASIDE'
'and' is the link.
(Other definitions for set aside that I've seen before include "Lay by" , "The policy of taking land out of production to reduce crop surplus" , "EU's agricultural scheme" , "Discount" , "agricultural policy" .)