1
general::
Also, lead up the garden path. Deceive someone. For example, Bill had quite different ideas from Tom about their new investment strategy; he was leading him down the garden path. This expression presumably alludes to the garden path as an intentional detour. [Early 1900s] Also see LEAD ON.
American Heritage Idioms
2
general::
Phrase(s): lead someone down the garden path [and] lead someone up the garden path
to deceive someone. • Now, be honest with me. Don’t lead me down the garden path. • That cheater really led her up the garden path.
McGrawhill's American Idioms And Phrasal Verbs