It is easy to grow them from seeds.
Why don't you let them bolt ... and collect your own acclimated seeds ?

I let one plant go to seed last year & I have a beautiful forest of rainbow chard this year in an area which was previouslly hardpan clay/weeds. It takes awhile for the seeds to dry (obviously I missed the window & they just sprouted where they fell), but I'm sure you'd recognize when they looked like the seeds that you normally plant if you watched them. I had every intention of collecting the seeds, but things got busy & I completely forgot about my experiment. Anyway, i'm very happy with the volunteer chard & they're doing a great job choking out most of the weeds that used to grow there.

OK, I think I'll pull all but one and get what I get this fall.
Thanks all! Nancy

It would be best to let a few go to seed. Since yours are already flowering, all you need to do is worry about letting the plants do their thing and strip the seeds off when they are ready. Below is a link on how to save seeds.

Rodney

Here is a link that might be useful: Saving Seeds

Unless you plan to grow ACRES of Chard, ONE plant will be more than enough. I'm letting one bolt right now myself. It's about 8 feet tall and has hundreds, if not thousands, of seeds. You may want to stake it.

Kevin

I pulled up all but one before I read this. I only need a few for the 2 of us.
Nancy