The current ones don't seem to be growing all that fast at this point,.. that's normal. They are "growing roots".. working hard underneath. Once they have built their root system, you will SEE growth.
Is it too late to start perennials from seed? I also have some Cardinal Flower and Delphinium I'd like to try.
Delphiniums and cardinal flowers need a cold period (cold stratification) to germinate, so it would be best to wait to winter sow them next January, unless you want to leave them in the fridge for about 6 weeks. Yet, by fall, they would not have established enough of a root system to make it through the winter, I would think.
Good luck, Adina,
Anne-Marie

I like to experiment. If you have quite a few seed and three or five wouldn't be missed go ahead and plant three or five now. Maybe they'll grow, maybe they won't, but if they do you'll be that much further ahead. You can always plant the rest of the seed in the spring.

Here is a link that might be useful: my website

These seeds have been in the fridge all winter, so they have had their cold period. I think I will plant a few and see how it goes and then winter sow the rest. Thanks for the advice.

adina,
I have to warn you on the Delphiniums. I don't know if it was voles or chipmunks or just the cold, but the Delps I started last summer and put in the ground in August were doing beautifully. I mulched them well and come March-April...NO sign of them.

I've had the same trouble with Delphiniums and I am determined to keep trying every location in my yard until I get it right...LOL....also same problem with Lupines.

I have one delphinium that's doing great, ready to bloom. I have a few others planted quite close by -- same bed, just a little further to the left or right. They are doing poorly. I wintersowed some this year. They are short, but coming. I've got one in the front yard, light blue, that just takes off every year, probably trying to peek out of the jungle I've got it in (basically a salad bed of jupiter's beard, bearded iris, miniature rose, thrift, blue-eyed grass, lamb's ear, rose campion, bee balm, painted daisy, icelandic poppy, japanese primrose, columbine, and probably something else I'm forgetting, surrounded by house or concrete walkway and driveway). That seems to be my happiest one, and he just gets morning sun and early afternoon.

Lupine... I have had mixed success there, too. This is the first year they have all seemed to really enjoy where they're planted (esp. the reddish one with eight blooms!)