It’s way above my attempts at horticulture! (4,6)
I believe the answer is:
roof garden
'horticulture' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'it's way above my attempts' is the wordplay.
I cannot really see how this works, but
'way' could be 'rd' (short for road) and 'rd' is present in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found in the answer.
This explanation may well be incorrect...
'at' acts as a link.
Can you help me to learn more?
(Other definitions for roof garden that I've seen before include "High-level greenery" , "where domestic growth high?" , "that's grown at highest level" , "Elevated area of greenery" , "where domestic growth is highest" .)