I use parks sponges. They are excellent and I get excellent results. They are the only thing that I can count on for certain in the whole daylily cycle. Lyle also used them till recently when he just got to many seedling to make it doable. The roots grow down and just stay happy and keep growing and growing. The good thing is tho, not the long roots, but the ability for the roots in the sponge to get really fat. Almost better than that, is the transplanting. There is no shock to speak of and the plants are able to stand up and be supported. Leslie makes fun of me over my sponges, but if you cant get the seedling to get going good for you, your dead in the water...so to speak.
I just went out and took some pictures of some. Darned if someone hasnt moved the cord to download. errr well Ill keep looking for that.