How to Join Crochet Seams with Whipstitch
The whipstitch is best for joining crocheted rows made of the shorter stitches, such as single crochet. You join the crochet pieces by whipstitching the row-ends together (when sewing the side seams of a garment), or you may work in the tops of the stitches (when you’re sewing shoulder seams or motifs).
The key to joining seams successfully is to match up the crocheted stitches on each side of the seam, using straight, even whipstitches, without pulling too tightly:
Position the pieces with right sides (or wrong sides) facing each other.
Match the stitches across each side edge.
Using a yarn needle and matching yarn, weave the yarn back and forth through several stitches on one of the pieces to secure the end.
Be sure to use yarn that matches in terms of weight and fiber. For example, if you used 100% wool yarn for the crocheted piece, then use the same for the whipstitching. Regular embroidery floss or sewing thread doesn't have the same resilience and could cause uneven pulling and stretching.
Insert the needle and pull the yarn through the inside loops of the first 2 corresponding stitches of the 2 pieces to be joined.
Pull the yarn tight enough so that the pieces of fabric rest fairly snug against each other, but not so tightly that the stitches become distorted.
Draw the needle up and over the 2 loops of the first stitch.
Don't over-tighten the yarn!
Repeat the two preceding steps across the edges to be joined.
Continue until you reach the end of the join.
At the end of the seam, weave the yarn back through several stitches to secure.
You've completed a whipstitch seam.
The whipstitch can create a decorative seam on your crochet work, especially when you’re sewing motifs together. With the wrong sides of the motifs facing and their stitches matched across each edge, sew the motifs together through the back loop of the stitches only. This technique creates a raised ridge on the right side of the work.