Springs when no buds burst (6)
I believe the answer is:
bounds
'springs' is the definition.
(I know this)
'no buds burst' is the wordplay.
'burst' indicates an anagram.
'no'+'buds'='nobuds'
'nobuds' with letters rearranged gives 'BOUNDS'.
'when' is the link.
(Other definitions for bounds that I've seen before include "borderlands" , "Leaps, restrictions" , "Borders or jumps" , "Limitations; leaps" .)