paper mulberry
楮 refers specifically to the paper mulberry tree, a plant whose bark is used to make traditional Japanese paper (washi).
楮 combines 木 (tree) with 者, which likely contributes the sound. The character was created to name the paper mulberry tree.
The tree radical 木 beside 者 suggests a specific tree: the paper mulberry. Imagine a craftsman (者) harvesting bark from this tree to make paper.
For チョ, picture a paper mulberry tree growing in a small, tidy garden: the word 'chore' (チョ) reminds you of the careful work of making paper from its bark.