Plant in the best area (4)
I believe the answer is:
tare
'plant' is the definition.
(tare is a kind of plant)
'in the best area' is the wordplay.
'in' indicates the answer is hidden within the clue.
'TARE' can be found hidden inside 'best area'.
(Other definitions for tare that I've seen before include "Moved very quickly" , "Vehicle weight minus fuel and load" , "Allowance made for the weight of the container in which goods are packed" , "Vessel's weight" , "Vetch plant" .)