why not leave them as is... to avoid transplant shock.. but flag them .. just a stick stuck in the ground... to remind you ...

and then move them in fall ... when there will be less transplant shock ...

if they just sprouted this spring.. the only problem you might have.. is the level of your expectations... a lot of perennials dont really do much that you can see.. the first year. ... they are growing a root mass...

if you have many.. do it both ways.. and discover for yourself.. which is best in terms of plant performance ....

ken

I pot up many seedlings, but usually do this in the Spring. Sometimes I pot up the winter-sown seedlings to let them put on some size before planting in the garden. This seems to increase their chance of survival. I just planted out some nice 6 inch Foxgloves yesterday and the day before, that I had potted as tiny seedlings and let grow on for 4-6 weeks.

I think you can pot up some Rudbeckia seedlings now if you want. If they are growing in a crowded littIe bunch they are probably competing for resources and won't grow optimally anyway. I would keep them some place easy to tend, where they only get a half day of sun (so they don't fry), and keep them well watered. Use a diluted liquid fertlizer about once a week.

Or you could thin them out in the patch, pamper a little, and transplant in fall.

I do it all summer long. If I see and recognize a seedling that I'd like elsewhere, I'll pot it up and stick it in the shade for a few days. Most of the time, they rebound just fine.

I yanked up 2 common milkweed sprouts that were in a bad spot & stuck them in a pot. They sulked for about 10 days, but finally started adjusting and started standing tall. And they HATE to be moved...