With right side facing join Yarn C to right hand corner as indicated.
Rnd 1: ch1, 3 dc, dc in each st to next corner, 3dc in ch2sp, dc in each st to next corner, 3 dc in last st, turn work 90 degrees and continue working dc evenly along the rough edge, sl st to first st. 194 sts.
Rnd 2: dc in each st around, working 2 dc in each corner st. Fasten off and weave in ends. 197 sts.
Change to Yarn B
Rnd 3: ch2, *5tr, skip 1 st, dc, skip 1 st; rep from * to end, sl st to 1st tr, sl st in next 2 sts, do not fasten off. 300 sts