How long for comfrey cuttings to emerge?

I just planted over 120 root cuttings into the side of a hill as part of an erosion control project. I’m watering 1-2x per day (light waterings so it can soak in). How long until I should see leaves emerge above ground? These are Bocking 14.

In other news, I was given a mostly wilted True Comfrey division earlier in the summer. I planted it and watered well for a week or so and then forgot about it. Of course there’s no sign of life at this point. Could the roots still be alive and come back in the spring?