Do some gardening (4)
I believe the answer is:
weed
'do some gardening' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for weed that I've seen before include "Unwanted plant - cannabis" , "Marijuana (slang)" , "Hoe to remove it" , "Intrusive plant; weak person" , "Useless plant - useless person" .)