The poem starts with a small, familiar problem: a hot, sticky night with no air conditioning, and no blanket that feels right. From there the speaker's wish turns into something stranger and more interesting. What he wants is moss, the soft green edge along a stony path, something that grows on its own, "without our say-so."
Then the poem zooms in. That smooth fuzz is really a crowd of separate plants, each one destined to send up tiny "green feathers," to learn to ration its water in a drought, and finally to wait its turn "in the common bed." The last phrase quietly nods to a grave, so the cozy bedtime image carries a thought about death and belonging.
The mood is drowsy, tender and gently humorous, with a calm acceptance underneath. The speaker seems comforted by being one small life among many, all part of the same living cover.