Foundation, col A - Ch4, sl st in 1st ch to join.
Rnd 1 - Ch3 (counts as dc), 15dc into the ring. [16dc]
Rnd 2 - Sl st yarn into any st. Ch4 (counts as 1dc and ch1), * 1dc in next st, ch1, rpt from * 14 more times, sl st into ch3 to join. [16dc and 16 x ch-1 sps]
Rnd 3 - Sl st into ch1-sp, ch3 (counts as dc) and 2dc in ch-1 sp, * 3dc in next ch-1 sp, rpt from 14 more times, sl st into ch-3 to join cut yarn, fasten off and weave in end. [48dc]
Rnd 4, col B - - Sl st yarn into any sp btw sts. Ch3, sk 3-sts, sc in sp btw next 2-sts, ch6, * sk 3-sts and sc in sp btw next 2-sts, (ch3, sk 3-sts, sc btw next 2-sts) 3 times, then ch6, rpt from * 2 more times, ch3, sk 3-sts, sc btw next 2-sts, ch3, sl st into 1st sc to join. [12 x ch-3 sps and 4 x ch-6 sps]
Rnd 5 - Sl st into ch-3 sp, ch3 (counts as dc), 2dc in same sp, (5hdc, ch2, 5hdc) into ch-6 sp, * 3dc into each of the next 3 ch-3 sps, (5hdc, ch2, 5hdc) into ch-6 sp, rpt from * 2 more times, 3dc into each of the next 2 ch-3 sps, sl st into ch-3 to join. [76sts and 4 x ch-2 sps]
Rnd 6 - Ch3 (counts as dc), 1dc in next 7-sts, * (2dc, ch1, 2dc) in ch-2 sp, 1dc in next 19-sts, rpt from * 2 more times, 1dc in next 11-sts, sl st into ch-3 to join, cut yarn and fasten off. [92dc, and 4x ch-2 sps]
Finishing - Use a yarn needle to weave in the loose ends and if necessary block the squares to ensure that they are of an even size and shape to make joining easier.