Songfacts®:

• Big Red Machine's Aaron Dessner and Justin Vernon began exchanging ideas for the follow-up to their self-titled debut album in spring 2019. However, the long weeks Dessner spent on the road with his band The National were exhausting, and he found himself in a bad place. It was during this low period that Dessner began penning "Birch." "I wrote it because I kind of was letting go of the idea of Big Red Machine," he told Uncut magazine. "I felt a little bit done, or a little bit lost with music. I was just kind of stuck, I think. But that song came out and I sent it to Justin. We hadn't talked in a while. I just said, 'I've been making this stuff, not feeling so well."
  
  Vernon immediately wrote the lyrics and vocal melody. His contribution enthused Dessner and reignited the whole process.
• Vernon's lyrics are difficult to decipher, but they appear to be about someone struggling with the way his life is working out. Eventually, he comes to terms with it and makes peace with his existence. But what Vernon means by "His birch ain't my tree" line is anybody's guess.
• By 2020, Dessner and Vernon got involved on Taylor Swift's lockdown project Folklore. Towards the end of the recording process, they played "Birch" for the pop starlet, who really loved the song. Swift asked if she could contribute harmony vocals, elevating the song further. It is one of two Taylor Swift features on How Long Do You Think It's Gonna Last?, the other being the single "Renegade."