Weary time in plant garden with elders (9)
I believe the answer is:
arboretum
'garden with elders' is the definition.
(elder is type of tree)
'weary time in plant' is the wordplay.
'weary' becomes 'bore' (as a verb).
'time' becomes 't' (abbreviation).
'in' is an insertion indicator.
'plant' becomes 'arum' (arum is a kind of plant).
'bore'+'t'='boret'
'boret' going inside 'arum' is 'ARBORETUM'.
(Other definitions for arboretum that I've seen before include "Botanical tree garden" , "area with great growth" , "there's high growth" , "Collection of elders, say" , "Tree display centre" .)