A landscaping owner running four crews could not tell you which properties still needed the fall cleanup

Every crew lead texts him at the end of the day. He used to write it on a whiteboard in the garage, now it is a group chat with forty unread messages by Friday. Twice this season a property got skipped because the message got buried. He is not disorganized, he just outgrew the whiteboard two years ago and never replaced it with anything. How do you track work across crews once it stops fitting in your head?