Top area almost cultivated for south African shrub (6)
I believe the answer is:
protea
'south african shrub' is the definition.
(type of bush)
'top area almost cultivated' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'cultivated' is an anagram indicator.
'top'+'area'='toparea'
'toparea' with its last letter taken off is 'topare'.
'topare' with letters rearranged gives 'PROTEA'.
'for' is the link.
(Other definitions for protea that I've seen before include "Ascend" , "South African shrub" , "S. African shrub; to pear (anag.)" , "South African evergreen" , "S.African flowering shrub" .)