Money tree planted by Conservative (4)
I believe the answer is:
cash
'money' is the definition.
(cash is a type of money)
'tree planted by conservative' is the wordplay.
'tree' becomes 'ash' (ash is a kind of tree).
'planted by' is a charade indicator (letters next to each other).
'conservative' becomes 'C' (UK political abbreviation).
'ash' after 'c' is 'CASH'.
(Other definitions for cash that I've seen before include "Funds" , "Spondulicks" , ""Readies"" , "Hard currency" , "bread" .)