Propagates vegetables round back of smallholding (6)
I believe the answer is:
begets
'propagates' is the definition.
'vegetables round back of smallholding' is the wordplay.
'vegetables' becomes 'beets' (beet is a kind of vegetable).
'round' indicates putting letters inside.
'back of' suggests the final letters.
The final letter of 'smallholding' is 'g'.
'beets' going around 'g' is 'BEGETS'.
(Other definitions for begets that I've seen before include "Becomes the father of, as in the Bible" , "Fathers or gives rise to" .)