Ogres destroyed prickly evergreen (5)
I believe the answer is:
gorse
'prickly evergreen' is the definition.
(I've seen this in another clue)
'ogres destroyed' is the wordplay.
'destroyed' indicates anagramming the letters.
'ogres' with letters rearranged gives 'GORSE'.
(Other definitions for gorse that I've seen before include "Spiny heathland shrub" , "Prickly moorland plant" , "Spiny yellow-flowered shrub" , "Welsh assembly" , "Spiky shrub" .)