Smashing shop deal for plant (8)
I believe the answer is:
asphodel
'plant' is the definition.
(type of flower)
'smashing shop deal' is the wordplay.
'smashing' indicates anagramming the letters.
'shop'+'deal'='shopdeal'
'shopdeal' anagrammed gives 'ASPHODEL'.
'for' acts as a link.
(Other definitions for asphodel that I've seen before include "Old shape (anag) - plant" , "Lad hopes (anag) - flower" , "Lily-like plant, the flower of death to ancient Greeks" , "Shop deal (anag.)" , "Mediterranean plant" .)