Eric Clapton wrote this with Bobby Whitlock, who played several instruments on the album. Whitlock told Songfacts: "'Keep On Growing' was a jam. We had one called 'Airport Shuffle.' It wasn't called 'Keep On Growing,' it was just a jam. We jammed in front of 50,000 people, we would open our shows by just jamming. Now there are bands that do nothing but that. It was a jam we did during the sessions. They were going to can it because it was an instrumental. It always gave us something to loosen up with. You take all the vocals off, and you've got a great instrumental.
They were going to keep it off the record, and I said, 'No man, you can't do that, this is too good.' I said, 'Give me 20 minutes,' so they stopped what we were doing and chilled out and I took a pencil and paper, went out to the lobby at Criteria - the studio we recorded at in Miami - and wrote the melody and the lyrics. They just fell out of me. I went back in and sang it. They turned a tape on and I tried to sing it myself and it just didn't come off right. They loved the song and what I'd done to it, so I told Eric, 'Why don't we do this like a Sam & Dave thing - you sing a line, I sing a line, we'll sing a line together.' We did it like that and it worked out. We did it right on the spot. That particular song was fresh picked, straight off the vine. What you hear on the Layla album was the first performance."