Herb produced by your old-fashioned setter (5)
I believe the answer is:
thyme
'herb' is the definition.
(I know that thyme is a type of herb)
'by your old-fashioned setter' is the wordplay.
'by' is a charade indicator (letters next to each other).
'your old-fashioned' becomes 'thy' (archaic word for 'your').
'setter' becomes 'me' (the setter of the clue).
'thy' next to 'me' is 'THYME'.
'produced' is the link.
(Other definitions for thyme that I've seen before include "Seasoning plant" , "something fragrant?" , "Culinary herb of the mint family" , "Culinary adjunct" , "Aromatic ingredient" .)