Around start of October plum tree's chopped up for fuel (9)
I believe the answer is:
petroleum
'fuel' is the definition.
(petroleum is a kind of fuel)
'around start of october plum tree's chopped up' is the wordplay.
'around' is an insertion indicator.
'start of' suggests taking the first letters.
'chopped up' indicates anagramming the letters.
The initial letter of 'october' is 'o'.
'plum'+'tree'='plumtree'
'plumtree' anagrammed gives 'petrleum'.
'o' placed into 'petrleum' is 'PETROLEUM'.
'for' acts as a link.
(Other definitions for petroleum that I've seen before include "Hydrocarbon oil" , "Oil well product" , "Fossil fuel" , "Source of fuel" , "Crude oil" .)