Grow less edelweiss, initially, after Charlie cuts grass (6)
I believe the answer is:
recede
'grow less' is the definition.
(to recede is to grow less or decrease)
'edelweiss initially after charlie cuts grass' is the wordplay.
'initially' indicates taking the first letters.
'after' is a charade indicator (letters next to each other).
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'cuts' means one lot of letters goes inside another (some letters cut their way into other letters).
'grass' becomes 'reed' (I've seen this before).
The initial letter of 'edelweiss' is 'e'.
'c' put within 'reed' is 'reced'.
'e' put after 'reced' is 'RECEDE'.
(Other definitions for recede that I've seen before include "Decree (anag) - ebb" , "Move backward" , "Decline" , "Go back, ebb" , "Start balding" .)