Mark, in a part of the garden, shunned drink (9)

I believe the answer is:
abstained
'shunned drink' is the definition.
The answer and definition can be both to do with social activities as well as being past participle verbs.
Perhaps you can see an association between them that I can't see?
'mark in a part of the garden' is the wordplay.
'mark' becomes 'stain' (synonyms).
'in' indicates putting letters inside.
'a part of the garden' becomes 'abed' (I can't justify this - if you can you should believe this answer much more).
'stain' placed within 'abed' is 'ABSTAINED'.
Can you help me to learn more?
(Other definitions for abstained that I've seen before include "chose not to vote" , "was non-committal" , "kept dry" , "avoided port?" , "went on the wagon" .)
