How shall the summer arise in joy,
Or the summer fruits appear?
The poem’s final stanza, which is made up of two lines, poses a question to the speaker’s parents. Resuming the thought from the previous stanza, the speaker asks his parents how can summer be enjoyable when there is a lot of destruction happening within him. His freedom and joy are clipped and thrown away, and yet, he is expected to be happy and content.

He wonders how a plant can produce fruit when the bud and blossoms are plucked away. Likewise, how can a child grow into a talented, caring, creative, and successful person if the very childhood is stolen away from them?

The poem ends in a rhetorical question posed not only to the parents but also to society. The poem is a call to action against the constraining, cage-like educational system and the intolerable pressure and expectations forced upon the kids by their parents.
When schools become prisons
National Council of Educational Research and Training (2008). Honeydew. The School Boy-William Blake (pp. 83 - 84). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.