Spend time after cultivating vines (6)
I believe the answer is:
invest
'spend' is the definition.
(I know that invest is a type of spend)
'time after cultivating vines' is the wordplay.
'time' becomes 't' (abbreviation).
'after' is a charade indicator (letters next to each other).
'cultivating' indicates anagramming the letters.
'vines' with letters rearranged gives 'inves'.
't' put after 'inves' is 'INVEST'.
(Other definitions for invest that I've seen before include "Put money into a company" , "Eg, buy stocks and shares" , "sink" , "Place money in a scheme" , "Put money into shares, property, etc" .)