Vegetable we had planted in southeast (5)
I believe the answer is:
swede
'vegetable' is the definition.
(I know that swede is a type of vegetable)
'we had planted in southeast' is the wordplay.
'we had' becomes 'we'd' (contraction of 'we had').
'planted in' indicates putting letters inside.
'southeast' becomes 'SE' (synonyms).
'wed' placed inside 'se' is 'SWEDE'.
(Other definitions for swede that I've seen before include "Man from Malmo" , "Scandinavian - vegetable" , "A turnip, or a Scandinavian" , "North European" , "Someone from Gothenburg" .)