Rip up root for processing as a source of scent (9)
I believe the answer is:
potpourri
'a source of scent' is the definition.
(a scented mixture of plants)
'rip up root for processing' is the wordplay.
'for processing' indicates an anagram.
'rip'+'up'+'root'='ripuproot'
'ripuproot' is an anagram of 'POTPOURRI'.
'as' acts as a link.
(Other definitions for potpourri that I've seen before include "assortment of botanical stuff?" , "Mixture of petals, spices etc." , "Mixed bag - rip up root (anag)" , "hodgepodge" , "Selection" .)