Many thanks again Ken. I think I should remove some of the top soil then add mulch, just to not have crowns too deep. I see what you say about big clumps sitting above the soil with Stella and Little Show Stopper (the biggest clumps I have). But all the others seems always too deep in the ground.
The empty bed will be not in use until autumn I think, if the seedlings grow (a couple of them show signs of new growth) enough they will go in that place hoping they will be big enough for winter.