"Salley" means "willow", so the first lines mean the same thing. But if you mean the US song that the Everlys recorded, I can't really see any resemblance beyond that line. The tunes don't seem to have much in common. Maybe it's just a stock opening line like, "As I walked out one morning..." etc, which Yeats (who wrote Salley Gardens) picked to give it a folksy feel?

Marje