The Poplar Response

I was assigned the poem The Poplar. Before reading this I looked up what a poplar was, I wasn't sure. I learned that it is a large tree that is a part of the willow family. This poem tells the story of a tree that grows outside of a house that I believe is the home to an older man. This poem is told in a couplet rhyming scheme, with AA BB CC. This makes reading it very simple.
My belief was that the man in the poem was peering out of his window at the tree, and a boy and girl who interact beneath it. It seems as though the man goes off into a memory, a flashback of sorts. He mentions a different time period, "And she-she seems to hold a dim/ Hand mirror with an ivory rim/ Framing a lawn, and her, and me/ Under the prototypic tree,/ Before a pillars porch, last seen/ In July, nineteen seventeen". This part is different than the rest. He uses himself in the context with the girl, instead of "a boy in black", and the poem itself was written in 1952, and he references something that hasn't been seen since 1917. The poem also mentions, "Of Populus that taps at last/ Not water but the author's past." He had mentioned before that the poplar was a dowsing tree, but in this case, the tree reaches for his memories, not a water supply.
By analyzing this poem, I realized that this was a memory about his past, about an old love, and about a specific time under a poplar tree in his front lawn.