I made this with double pointed needles and worked all 4 pieces of each square at the same time -no sewing required. I did change the last few rows. Work chart until the leaf pattern is finished (row 30). Then work as follows:

Row 31: p1, (yo, p2tog) continue to last 2 sts, yo, p1, yo, p1 -35 sts in each quarter

Row 32: p1, knit to last st, p1

Row 33: p1, yo, purl to last st, yo, p1

Row 34: p1, knit to last st, p1

Repeat row 31-33, once

Cast off as follows: k1, yo, k1, slip the first k and the yo over the last k1, then yo, k1, slip the k and yo over the last k1. Continue to end of round.

This makes a nice elastic cast off edge and helps the square lay flat.