I grew Echinacia/coneflowers from seed back in 2009/2010 the first time I tried winter sowing and had good germination. I didn't expect blooms the first season based on what I'd read on the WS forum. The plants bloomed the second season but that's in my zone 6 garden, which is quite a bit warmer than your Z3. It's no more than a guess but perhaps they take a season or two longer to bloom in your zone.

Good luck & hope you see blooms in the very near future.

Echinacea blooms the 2nd year from seed for me too. I am just getting the first flowers coming out now.

If your plants are 3 feet tall, you must have blooming stalks shooting up. Aren't there buds at the top?