Drainage sorted for shrub (8)
I believe the answer is:
gardenia
'shrub' is the definition.
(gardenia is a kind of shrub)
'drainage sorted' is the wordplay.
'sorted' indicates anagramming the letters.
'drainage' anagrammed gives 'GARDENIA'.
'for' acts as a link.
(Other definitions for gardenia that I've seen before include "Drainage for shrub with white or yellow flowers" , "bloomer!" , "Drainage (anag) -- plant" , "Bad drainage can produce a fragrant flower" , "Fragrant shrub, red again (anag.)" .)