Garden in China, not the first (7)
I believe the answer is:
rockery
'garden' is the definition.
(rockery is a kind of garden)
'china not the first' is the wordplay.
'china' becomes 'crockery' (I've seen this before).
'not the first' means to remove the first letter.
'crockery' with its initial letter taken away is 'ROCKERY'.
'in' acts as a link.
(Other definitions for rockery that I've seen before include "Part of garden" , "Garden alpine area" , "Garden feature with alpines" .)