Got bigger when cultivated (5)
I believe the answer is:
grown
I believe this is a double definition.
'got bigger' is the first definition.
'cultivated' is the second definition.
(I've seen this in another clue)
'when' is the link.
(Other definitions for grown that I've seen before include "Fully developed" , "Cultivated" , "Mature; raised" , "increased in stature?" , "Wrong (anag)" .)