Interesting that you're both hearing things other than "green." I've been trying to rack my brains along those lines as well. I keep coming up with similar ideas that fit with the syllables he's singing but which don't make any sense lyrically.
I also considered "green hair" because maybe a willow tree looks like it has green hair.
But what puzzles me, if that's the case, is the word after "all around." It definitely seems to start with a w. See, if "green hair" was right then "All around her green hair" would probably make more sense than anything else I've come up with, but he's not singing "her." It's baffling.