One idly passing time arranging flora around the end of June (6)
I believe the answer is:
loafer
'one idly passing time' is the definition.
'arranging flora around the end of june' is the wordplay.
'arranging' indicates anagramming the letters.
'around' indicates putting letters inside.
'the end of' says to take the final letters.
The last letter of 'june' is 'e'.
'flora' is an anagram of 'loafr'.
'loafr' enclosing 'e' is 'LOAFER'.
(Other definitions for loafer that I've seen before include "Idle person" , "Style of shoe" , "Layabout" , "Idler; casual shoe" , "Lazy type" .)