They are like potatoes and mine are still not showing. Watch these guys -- they spread like crazy.

Good words of warning above :-) Many years ago I planted what was simply labeled "perennial sunflower" only to determine later that it was in fact Jerusalem artichoke. It did produce lovely flowers but what a PITA!! Those tubers spread everywhere and at considerable distance from the original planting. I was digging them out for years.

Thank you, dottyinduncan and gardengal, for information.
I have planted them in place where they will not have a lot of possibility to spread and i am hoping to eat tubers.
I possible will need to add some inground surrounding like i did for horseradish.
How deep their roots go?

Not very.

Mine have just been beginning to come up in the past 10 days or so.

mine are also not up yet.

they spread pretty aggressively, i have mine in my sidewalk strip, where i mostly put annuals and grasses and things i can pull out easily.

the roots taste great. little bit tricky to cook. great in soups.

Thank you. Looks like I need just wait for now.
I want to eat them raw with raw beets (this a recipe that my doctor gave me).

FAIR WARNING: the starch in the roots is inulin.

"Inulin is indigestible by the human enzymes ptyalin and amylase, which are adapted to digest starch. As a result, inulin passes through much of the digestive system intact. It is only in the colon that bacteria metabolise inulin, with the release of significant quantities of carbon dioxide, hydrogen, and/or methane. Inulin-containing foods can be rather gassy, particularly for those unaccustomed to inulin, and these foods should be consumed in moderation at first."