Mysterious objects in lush heather, buried by earth (9)
I believe the answer is:
esoterica
'mysterious objects' is the definition.
(I've seen this before)
'lush heather buried by earth' is the wordplay.
'lush' becomes 'sot' (both can mean a drunk).
'heather' becomes 'erica' (the plant genus Erica includes heather plants).
'buried' is a charade indicator (letters next to each other) (in a down clue, some letters go beneath others).
'by' is a charade indicator (letters next to each other).
'earth' becomes 'E'.
'sot'+'erica' is 'soterica'.
'soterica' after 'e' is 'ESOTERICA'.
'in' acts as a link.
(Other definitions for esoterica that I've seen before include "obscure knowledge" , "specialist publications" , "Specialized publications" , "Mysterious items -- ciao trees (anag)" , "Highly specialised subjects" .)