Mum, after one, is able to find container (6)

'container' is the definition.
(ashcan is a kind of container)

'mum after one is able to' is the wordplay.
'mum' becomes 'sh' (I've seen this in other clues).
'after' says to put letters next to each other.
'one' becomes 'a'.
'is able to' becomes 'can' (I've seen this before).
'sh' after 'a' is 'ash'.
'ash'+'can'='ASHCAN'

'find' acts as a link.