Digging/Replanting Artichokes in Northern Climates

I'm growing in zone 5a and the farm that I work at is growing artichokes. Rather than starting them from seed every year, I'm wondering if we could dig up the roots and store them until the next season in order to get a better crop. I remember reading that in areas where they are grown as a perennial, the chokes could be cut off before getting large the first season so that they establish better. Maybe we just shouldn't be growing artichokes anyhow? Ha.
Any experience from northern growers here? Just thought I'd ask. Thanks! Joe

i have had cardoons perennialize in northern ohio... zone 5b... and I don't think it would be too difficult to cross them with artichokes as they are in the same genus (cynara)
i have been eating the flower heads in the same way as artichokes and have noticed that they are just as good (although slightly smaller.... this could be taken care of with some breeding work)... plus you can blanch the stems and eat that part of the plant too... it seems like planting and replanting the artichokes every year and/or growing from seed can both be an intensive process... out of four plants that I had last year two of them died but reseeded (i have four little seedlings in the plant guild i used them in ) and two of them have made it through the winter and are now flowering again for their second year.... oh ya.... the flowers are AMAZING!