My primary suggestion would be not to plant daylilies in fall in your area. I don't think adding compost would help, unless the soil needs improving anyway (but don't amend just the planting holes, do the whole bed).
One question, though, when you planted them did they have a lot of root, and did you plant them on top of a mound of soil made in the middle of the planting hole, with the roots spread outwards over it, as described in the AHS FAQ?:
http://www.daylilies.org/AHSFA...
Having some of the roots sideways, as established daylilies grow, may help reduce heaving. I would assume root-pruned new transplants would be more likely to heave as well.
