Why not both?

Plant each seedling into a medium to larger sized pot and sink each pot into a holding bed.

Make sure the pots are deep as butterfly bushes can get decent tap roots in a year's time.

You can use any system you want to mark them what color the flowers are when they bloom and they will bloom!

Most of them will bloom if you put them in large pots. I have put 2 per pot and had them bloom. I used 1 gallon pots, I think. In my view, pots are better because you won't lose any of the root system when you replant them.

Becky

Thanks. I've got plenty of 1gallon+ sized pots. I think I'll plant them in there and mulch the containers to keep the roots cool. I don't really want to dig them out next spring.