Grows pot in former outskirts of Dumfries (7)
I believe the answer is:
expands
'grows' is the definition.
(expanding is a kind of growing)
'pot in former outskirts of dumfries' is the wordplay.
'pot' becomes 'pan' (I've seen this before**).
'in' indicates putting letters inside.
'former' becomes 'ex'.
'outskirts of' says to hollow out the word (remove centre letters).
'dumfries' with its centre removed is 'ds'.
'ex'+'ds'='exds'
'pan' going within 'exds' is 'EXPANDS'.
(Other definitions for expands that I've seen before include "Enlarges" , "gets bigger" , "Becomes larger" .)