Tedious talk about border plant (8)
I believe the answer is:
primrose
'plant' is the definition.
(primrose is a kind of plant)
'tedious talk about border' is the wordplay.
'tedious talk' becomes 'prose'.
'about' indicates putting letters inside.
'border' becomes 'rim' (I've seen this before).
'prose' placed around 'rim' is 'PRIMROSE'.
(Other definitions for primrose that I've seen before include "Spring woodland flower" , "Yellowish" , "Woodland plant with pale yellow flowers" , "Yellow spring flower from promiser" , "Rip morse up to find the flower" .)