In temperate climates, the flowers of sunchokes are generally sterile. But even if you were able to get fertile seed & grow it, there is no guarantee that you would get a plant similar to the original.

Sunchokes are most often reproduced vegetatively, by tubers. The varieties presently in circulation are clones, probably of hybrids created some time in the past. Hybrid seed will not grow true to type. A similar situation exists with most potatoes grown today; if you plant seed from a potato, you are likely to get plants with a wide range of characteristics.

Since each JA tuber planted can produce 50 or more tubers in a season, that is the preferred method of reproduction. But if you are able to get seeds & have the space to experiment, it might be fun to try growing them.

Where ever you planted them...you're probably going to have them for life...especially in a zone 8. They're almost impossible to get rid of. Enjoy.

Never had seeds on my plants or found the listing for seeds, only tubers.
The first sunchokes I plant feed the deer & moles.
I now have 3 kinds growing.