Hi
@coconut,
There are a lot of companies that offer sweet potato slips and they are all sourced by just a couple of the same growers. (That is why they all seem to carry the same varieties) To answer your question, yes, the slips are rooted (or should be). When they arrive, they always look pretty bad. A lot of folks do not know what slips are and think that they are dead, or even worse, they kill them by taking them out of the shipping material and plopping them out into the garden.
What is recommended is to immediately open the package and get the slips moved into a jar of water (think cut flowers in a vase). I usually leave them in the water, in an unheated greenhouse or outside in a partially sunny location, for a few days to perk them up and harden them off a bit before planting. And like
@drdawg said, they
do not tolerate frost.
If folks are looking for a source, I would highly recommend my friend David at the New Hope Seed Company -
http://www.newhopeseed.com/swe.... He is a small seed farmer in Tennessee, one of the seed growers for us, and offers Tennessee grown sweet potato slips. And his prices for potato plants include free shipping.
Hope this helps,
Mike