A plant the Poles have to pay out for (5)
I believe the answer is:
pansy
'a plant' is the definition.
(pansy is a kind of plant)
'pay out for' is the wordplay.
'out' is an insertion indicator.
'for' becomes 'ns' (I can't justify this - if you can you should believe this answer much more).
'pay' placed around 'ns' is 'PANSY'.
'the poles have to' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for pansy that I've seen before include "Common garden flower" , "Species of violet" , "Cultivated viola" , "Garden plant with large flowers of various colours" , "Flower - effeminate person" .)