Yes, chop the leaves, bury them. The roots of a comfrey plant can go down 8 feet. It bring nutrients to the top of the soil. We also plant them around our bushes and our fruit trees. Also the flowers attract pollinators. Just make sure you get the kind that don't spread (bocking #4 and #14) https://fountain.fm/episode/p7OVkEgU0NjaMQomF1Tu