Slip knot onto hook, chain 21
Skip first 2 chains and half double crochet (hdc) in 3rd chain from the hook. Continue in each chain stitch to end of row.
ROW 2: Chain 2, turn work, hdc in each hdc across row.
ROWS 3-13: Repeat row 2
Finish off: cut yarn several inches beyond last stitch and pull yarn end through the last stitch remaining on the hook. Weave in loose ends.