More inexperienced Yankee in foliage (8)
I believe the answer is:
greenery
'foliage' is the definition.
(greenery is a kind of foliage)
'more inexperienced yankee' is the wordplay.
'more inexperienced' becomes 'greener' ('green' can be similar in meaning to 'inexperienced').
'yankee' becomes 'y' (phonetic alphabet: alpha, bravo, charlie etc.).
'greener'+'y'='GREENERY'
'in' acts as a link.
(Other definitions for greenery that I've seen before include "Trees" , "something naturally colourful?" , "fresh leaves on the tree" , "Decorative boughs" , "Verdure" .)