Seaming Together Norwegian CastOn Squares

Hi Knitters,
I am so new to knitting, I’ve managed to make a cute hat,and two very long scarves. I am making squares with a seed stitch and I used a norwegian cast on with each square. I now have 9 squares, I 'll need many many more, but I’m patient!
Each square measures 9x9-1/2 inches (not a square, haha) I have a problem, I don’t know why I used a norwegian caston but I can’t figure out if I should use the mattress stitch to seam them together and I don’t know If I will have a problem with the different caston and bind off edges Also, how do I seam the side edges together? .<img

Welcome to KH!
Your squares look beautiful. Seed stitch makes such a pretty fabric.
You should be able to use mattress stitch to join. You’ll use the first row of stitches rather than the cast on or bind off edges. You might also think about a crocheted edging if you crochet.

This video shows join for 2 bind off edges but same would apply to cast on and bind off edges.

Hi, you don’t know how much your compliment did for me. To have an experienced knitter say that what I have created was beautiful, WOW! I have so little confidence in myself, so you really made my day! Thank you for that! I didn’t see your answer at first so I posted again. I am going to delete that extra post if I can find out how, LOL. thanks again.