comfrey roots not growing?

I got some comfrey roots almost two weeks ago and nothing is coming up. Is this normal? How long does it take?

Two weeks, in a Zone 3 environment, is probably a tad too early to expect to see much results.
Comfrey is a nitrogen hog. Lawrence D. Hill (the developer of the Bocking series) recommends a heavy manuring prior to planting comfrey.

Good to know. Thanks

I am happy to report the first leaves are showing! I planted three in the ground and two are definitely growing leaves now. The third not (yet). I also have some root cuttings in pots and dug one up. There are tiny roots coming but no leaves yet. So patience I guess