How to Prune white comfrey?
Generally not required but old or fading foliage can be trimmed

white comfrey · Symphytum orientale
Grow in sun or partial shade in moist, moderately fertile soil. Whilst it may have the potential to become a nuisance, the risk is less compared to some other Symphytum species, but it self-seeds readily
Generally not required but old or fading foliage can be trimmed