Just lift and plonk will do fine. If you have some space in light shade that you'll keep free of weeds, should be just as good as in pots, if not better, especially foetidus.

If you can get them into deep, humous rich, NOT waterlogged soil, will do great.

I guess you like the red stems and tips of foetidus, this shows up really early in the seedlings. Foetidus grows big to flowering in 2 years, space them out and only keep those with the "reddest" stems. They grow better in the open ground and even if raised in pots should be planted out while really quite small in order to get long lived plants....they don't transplant very well.

Pots are handy for giving them away!!!

Have fun,

Cheers Greenmanplants