I have finished a baby blanket that came out great but as I was trying to add a border my blanket started to roll inwards. (I put 3 rows of single crochet then added a scalloped border....single crochet skip 1 then 5 double crochets.) I even undid it once and tried to crochet looser thinking maybe I was pulling too tight but that didn't work either. My crochet skills are very basic. Can anyone offer suggestions? I love the look of a knitted blanket with a border to finish it off. Patterns for crochet border would be appreciated also

Thanks
Vinci