Now is the time for the burning of the leaves

I came across this poem whilst I should have been working.  Its by Laurence Binyon and was written in 1942:

Now is the time for the burning of the leaves,
They go to the fire; the nostrils prick with smoke
Wandering slowly into the weeping mist.
Brittle and blotched, ragged and rotten sheaves!
A flame seizes the smouldering ruin, and bites
On stubborn stalks that crackle as they resist.
The last hollyhock’s fallen tower is dust:
All the spices of June are a bitter reek,
All the extravagant riches spent and mean.
All burns! the reddest rose is a ghost.
Spark whirl up, to expire in the mist: the wild
Fingers of fire are making corruption clean.

Now is the time for stripping the spirit bare,
Time for the burning of days ended and done,
Idle solace of things that have gone before,
Rootless hope and fruitless desire are there:
Let them go to the fire with never a look behind.
That world that was ours is a world that is ours no more.
They will come again, the leaf and the flower, to arise
From squalor of rottenness into the old splendour,
And magical scents to a wondering memory bring;
The same glory, to shine upon different eyes.
Earth cares for her own ruins, naught for ours.
Nothing is certain, only the certain spring.