Good to know. I'm not sure which brand I bought, whatever Home Depot had since it wasn't the right time to buy bulb fertilizer.
I garden organically so if what I bought isn't organic I'll switch to something that is.
I have lots of buds on the other peonies (except the NOID since it is more shaded). I hope to be amazed next year with their growth and even more blooms!
I bought my Bartzella potted like your SIL. It wasn't huge though. I only bought it because I felt sorry for the poor plants. They were all indoors with no natural light.