I'm not an expert seamstress, but maybe this will help. Do a basting stitch 1/4 inch from the bottom edge, all the way around. Gently pull the the threads to ease in the edge, taking in the slack just a bit. Press under along the stitching line, then turn or press under along the hem(fold)line and machine or hand stitch your hem. This should eliminate the "pucker" I think you're worried about.

That should do it. It has to be a very narrow hem. The hem should lie flat all by itself at center front and center back; you can make tiny snips to the basting stitch and press it up to even out the fullness at the sides of the dress if you need to.

You can try adding a stretch lace hem tape if the fabric is too hard to handle and won't press properly.

That's why I line them, to keep from having to try and do the hem, LOL.
Susan

Thanks ladies! That helped and I finally was pleased with it.

Susan, I'm intrigued...I always thought lining would be more of a pain but after dealing with that hemline, I'm willing to try lining one. Is there a trick to it? It seems like you'd just make the same dress (sleeveless, of course) and just sew it to the top shoulder seams?? no, you'd still have to hem that. Does anyone have a good link for me? LOL I tried Googling it but got nothing.

Sewing is fast becoming a lost art. :(

I did a lot of a-line skirts and dresses in the 60's. One way to handle it even on deep hems is to make little pleats or tucks in the underneath where you are stitching the hem. Just make sure the side seam and center front and back are straight.