Gardener employing Pole holding current degree β one earning a lot for the business (9)
I believe the answer is:
rainmaker
'gardener employing pole holding current degree one' is the definition.
I can't judge whether this defines the answer.
'earning a lot for the business' is the wordplay.
'earning a lot' becomes 'rain' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'for' says to put letters next to each other.
'the business' becomes 'maker' (maker is a kind of business).
'rain'+'maker'='RAINMAKER'
Can you help me to learn more?
(Other definitions for rainmaker that I've seen before include "Witch-doctor" , "happy to have cloud over his reputation?" .)