Tree starts to sprout twigs before anything else (5)
I believe the answer is:
first
'before anything else' is the definition.
(synonyms)
'tree starts to sprout twigs' is the wordplay.
'tree' becomes 'fir' (fir tree is a kind of tree).
'starts to' says to take the initial letters.
The initial letters of 'sprout twigs' is 'st'.
'fir'+'st'='FIRST'
(Other definitions for first that I've seen before include "to begin with" , "Coming before all others" , "best" , "Preliminary" , "Pre-eminent" .)