Notice, at end of dead heather, young plant (8)
I believe the answer is:
seedling
'young plant' is the definition.
(I've seen this before)
'notice at end of dead heather' is the wordplay.
'notice' becomes 'see' (notice can mean to spot or see).
'at end of' indicates one should take the final letters.
'heather' becomes 'ling' (synonyms).
The final letter of 'dead' is 'd'.
'see'+'d'+'ling'='SEEDLING'
(Other definitions for seedling that I've seen before include "Small plant" , "Young plant" , "Tiny plant" .)