Healthy pace starting in plant (9)
I believe the answer is:
speedwell
'plant' is the definition.
(speedwell is a kind of plant)
'healthy pace starting' is the wordplay.
'healthy' becomes 'well' (associated in meaning).
'pace' becomes 'speed' (I've seen this before).
'starting' is a charade indicator (letters next to each other).
'well' after 'speed' is 'SPEEDWELL'.
'in' is the link.
(Other definitions for speedwell that I've seen before include "bloomer?" , "Small plant, veronica" , "Flowering plant" , "Small creeping herbaceous plant with blue or pink flowers" , "Small blue flower of the genus veronica" .)