Possibly kill when there's little growth (5)
I believe the answer is:
shoot
This clue might be a double definition.
'possibly kill' is the first definition.
'shoot' can be an answer for 'kill' (shooting is a kind of killing). I'm not sure about the 'possibly' bit.
'little growth' is the second definition.
'shoot' can be an answer for 'growth' (I have seen 'New growth ' mean 'shoot' so perhaps 'growth' could also mean 'shoot'). I am unsure of the 'little' bit.
'when there's' is the link.
Can you help me to learn more?
(Other definitions for shoot that I've seen before include "Fire at the new branch?" , "Kill; part of plant" , "big game expedition?" , "Hit with a missile or take a picture" , "Use a gun; film" .)