I think if you don't transplant poppies and larkspur while tiny, they get stunted from the pot. Sometimes what I manage to get out early rewards me with a lot of growth, but some of this year's seedlings should have been better-developed before I stuck them in the rough spot I put them in.

I've definitely learned that once the pot is full of roots, those plants won't grow much until they get in the ground. And, it's easy to have an overgrown container dry out in the summer heat. Also, I have planted a lot of seedlings out in fall...and late fall...and that does not work well in my zone 5, even though it cools slowly because of the lake. The seedlings that have survived that are almost exclusively the ones that got a cold-frame of some sort. I lost a lot of nice seedlings last year :(

Karen