In my experience, over the long term, it really is better to hem the blanket, rather than just put in a row of machine stitching. Also, if you put your first row of single crochet over the hem, into the blanket below the hem, you run the risk of the hem folding or curling inside that first row after you wash it. And believe me, mommies don't have time to pick and iron those things most of the time. It may be a bit tedious, but there are three alternatives I have used with success. One is to hand stitch a row of buttonhole stitch around the blanket edge with crochet thread, then crochet into that. The second is to use a size 10 or 12 hook to pierce the material and pull the thread through and then use the larger hook to crochet. And the third is to use a sharp yarn needle to make the holes. Don't just poke a hole, but take the needle completely through the material to spread the threads in preparation for your hook. Do about a 12" worth of holes and crochet the first stitches, then another 12" and so on. Yes, it's labor intensive, but it is a labor of love, is it not?

I make a one inch hem....fold under 1/4 inch and then fld over so the hem is 1 inch....maching stitch. Then you can ke holes in the edge and only be poking through 2 layers of flannel.
An alternate is to use a tapestry needle and do a row of blanket stitch and then crochet your edging using that as a base.
Linda C

Donna, I have done the bit of using a size 10 on the first row and then changing to the size 6 called for in the instructions. I will try piercing it with a sharp yarn needle I recently purchased and see if it is better. Linda, I might try your method next time. Right now, I have it all hemmed and want to continue. Thanks for helping to problem solve. These crocheted edges do take a lot of time!

I've used a small awl to pierce the fabric.