Size H Hook (crochet hook sizes here)
Row 1 - Chain 20. In 2nd chain from hook double crochet (treble in England)
Row 2 - DC in each chain. When you get to the end, 3 chain then turn
Row 3 - 20 - Repeat row 2
Join edges either by sewing or crochet whatever you prefer
Scallop edge
Double crochet in the second stitch. Five more dc in same stitch.
Slip stich in 3rd stitch from the scallop.
Six dc in 3rd stitch from slip stich
Continue around the edge of the boot cuff.
Note: you may need to adjust the size depending upon the size of your calf and the thickness of the yarn. For the main part I only put the needle through one strand, rather than both of them which gave it a ridge effect.
