April in September

What song is in the sap of this brave oak-tree
That to the north-star faces,
Ravened each June by caterpillar masses
Till all its leaves are laces,
Poor shreds whose very shadow grieves the grasses?

I leave it then, but roses and the smoke-tree
Look from the lawn below it
And watch for that gold witch, Midsummer Weather,
With magic breath to blow it
Free of its foes, whose wings make mirth together.

Vital as Igdrasil, immortal folk-tree,
When I return, its losses
Are all restored, its fresh, soft foliage gleaming
With peach and citron glosses,
A Druid that is never done with dreaming.