Salad vegetable is hard unfortunately (6)
I believe the answer is:
radish
'salad vegetable' is the definition.
(I've seen this before)
'is hard unfortunately' is the wordplay.
'unfortunately' indicates anagramming the letters.
'is'+'hard'='ishard'
'ishard' anagrammed gives 'RADISH'.
(Other definitions for radish that I've seen before include "3 down" , "Pungent fleshy edible root eaten in salads" , "Small red salad vegetable" , "Hottish salad plant" , "Root vegetable used in salads" .)