Peeved now about the green being in poor condition (7)
I believe the answer is:
angered
'peeved now' is the definition.
'angered' can be an answer for 'peeved' (I've seen this in another clue). I am unsure of the 'now' bit.
'about the green being in poor condition' is the wordplay.
'about' indicates an anagram.
'being in' is an insertion indicator.
'poor condition' becomes 'ad' (I can't explain this - if you can you should believe this answer much more).
'green' anagrammed gives 'ngere'.
'ngere' going into 'ad' is 'ANGERED'.
Can you help me to learn more?
(Other definitions for angered that I've seen before include "Infuriated" , "En garde (anag.)" , "Enraged (anag)" , "Very annoyed" , "In high dudgeon" .)