It may be fruitful to curse housing thus (6)
I believe the answer is:
damson
'it may be fruitful' is the definition.
(a damson tree produces fruit)
'curse housing thus' is the wordplay.
'curse' becomes 'damn' (synonyms).
'housing' indicates putting letters inside.
'thus' becomes 'so' (synonyms).
'damn' going around 'so' is 'DAMSON'.
'to' acts as a link.
(Other definitions for damson that I've seen before include "Nomads (anag)" , "Small dark-purple plum" , "might one be in a jam?" , "Small plum-like fruit" , "sort of fruit" .)