FWIW this is a quote from the American Hemerocallis Society's 2002 Handbook chapter on daylily anatomy and physiology section on seedlings:
"For several weeks following the first flush of leaf expansion, no more leaves are apparent. Root growth, however, remains very active unless changes occur in environmental conditions."
Vermiculite does contain some nutrients (calcium, magnesium, potassium), and it also has a high CEC which helps hold on to added nutrients. But having said that, daylily seedlings do fine in vermiculite without added nutrients for at least a month after germination. After that I would certainly start a weak fertilizer or move them to a growing medium with fertilizer, which I think Cybersix is doing? (Edited for clarity).
