POETIC ANALYSIS: Robert Frost is pre-occupied with the description of birches, which are very slender trees with thin outer cover or bark which easily peels. These slender trees (birches) grow amidst other trees and swing from side to side making the speaker think that someone is swinging it, he says:
When I see birches bend left or right
Across the lines of straighter darker trees
I like to think some boy’s been swinging them
It is not only boys that swing the birches, “ice” do.
In fact, swinging alone does not make the birches to bend down and stay but ice can do so especially when the birches are covered by ice on a sunny winter morning after rain. The following lines capture this message:
“But swinging doesn’t bend them down to stay.
“As ice-storms do…“
The speaker reveals that when there is an ice storm after a rain, these birches are covered with ice which forces the slender trees to bend. As the “breeze” begins to blow, the birches are swayed about and the ice cove1ng the trees hit/clash among themselves and cause some clicking sound. As these ice on the birches hit amongst themselves, they crack and fall off. Then as the sun becomes hotter, the “ice on the birches begin to melt and pour down in torrent like an avalanche as observed by the speaker in these lines: Soon, the suns warmth makes them
Shed crystal shells,
Shattering and avalanching on the snow crust…
When this happens, it seems the dome of the heaven is falling down; (that is the sky). However, the poet goes on to suggest that though these birches may swing and bend, they never break as a result. But when they are bent for a very long time, they never seem to straighten up again. We can get this message on the concluding lines of the third and last stanza of the poem. They are dragged to the withered…
And seem not to break
Though once they are bowed
So low for long, they never right themselves.
What these lines try to suggest is that these slender trees (birches) may not break, no matter the nature of wind that swings them or ice storm that covers them. However, when they are dragged to “bow so low for long”, they may never become right again.