Removed undesirables from garden — both of us tricked, some might say (6)
I believe the answer is:
weeded
'removed undesirables from garden' is the definition.
'both of us tricked some might say' is the wordplay.
I cannot quite see how this works, but
'us' could be 'we' and 'we' is found in the answer.
This explanation may well be incorrect...
(Other definitions for weeded that I've seen before include "Took out garden invaders" , "Removed unwanted growth from garden" , "Removed invasive, unwanted plants" , "Cleared of uncultivated plants" , "Cleared garden" .)