For daylily seeds the stratification must be damp or it doesn't work. I found for some daylily seeds three weeks stratification wasn't enough and they did better with six weeks. In the original research on daylily seed dormancy it was suggested 1-2 months was appropriate for seeds stratified outdoors. You know stratification was inadequate in some way (too dry or too short for example) if germination afterwards still takes several weeks instead of a week or two. There was some negative effect on germination when stratification was too long in the research, I think it was longer than 3 months but would have to re-read the research again. You can read the abstract of the research here, scroll down past the first page:
http://www.jstor.org/stable/24...
