Plant Cockney poet found outside hotel (6)
I believe the answer is:
orache
'plant' is the definition.
(orache is a kind of plant)
'cockney poet found outside hotel' is the wordplay.
'cockney poet' becomes 'orace' ('horace' - I've seen this before - said with the 'H' dropped - a cockney accent.).
'found outside' is an insertion indicator.
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'orace' placed around 'h' is 'ORACHE'.
(Other definitions for orache that I've seen before include "vegetable" , "spinach substitute" , "Edible spinach-like plant of the genus Atriplex that thrives in arid areas" .)