Rose garden bane (6)
I believe the answer is:
aphids
'rose garden bane' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aphids that I've seen before include "Plant pests" , "Garden pests" , "Small insects like greenfly or blackfly" , "Small plant-sucking insects" , "Small insects like greenfly feeding on plants" .)