No stratification required. Relatively easy to germinate.

Swallowtail Garden Seeds website: "Kept at 65-70 F., germination is in 21-30 days. Seedlings are fragile and must be handled with care." I've winter sowed them and summer sowed them--great germination either way. They're late to come up in the spring, so mark where you planted them. This year I laid down cardboard & mulch over top of them by mistake. A couple of weeks later the mulch kept rising up higher and higher. When I looked to see what was going on, I saw my oldest clump of balloon flower coming up under it.

They have a long taproot and resent being disturbed so plant them where you want them. That being said, I dug mine up from my old house and brought them here 5 years ago and they never missed a beat. My blue ones get pretty tall and flop over so I usually whack them down to about 8-10" the last week of May. They stay in a compact clump and produce lots more flowers that way.

Thanks folks!

Nice thing with these, Gardenweed, is that they are dwarves so they have stayed very compact.

Paul..just a word of caution. If your plants are hybrids, and you mention they are dwarves so they might be. The seeds may revert back to the parent plant so you might not get dwarves!!!
Joann

I can't say for certain but don't think Paul needs to worry about them reverting. I also grow double white balloon flowers and they come back reliably season after season, growing just 18-22" tall. Right now they're loaded with plump seed pods that I will harvest once they're ripe enough.