The speaker addresses an oak tree in winter, speaking to it almost like a gentle instruction: let the leaves go, stand alone in the cold. There is some comfort in the image of squirrels sheltering in its hollows, but the tone is mostly quiet and watchful.
The second stanza shifts to the acorns beneath the tree. They are already swelling, each one carrying "your pattern," the whole blueprint of an oak in miniature. The tree's life seems to continue below its own branches.
Then the poem turns. The short list of things that shape the oak's future, "length of day, / strength of sun, / depth of rain, / the air," feels natural and steady, until "the axe" interrupts. That one blunt phrase brings in human power. The final lines say that the oak's future is "contingent / on the world," which sounds both humble and uneasy. The mood is calm and tender, with a shadow of worry underneath: the tree can endure winter, but not everything is up to it.