To make a shamrock, begin with a ch of 10 sts, sl st into a ring; ch 4 and make 24 tr into the ring, ch 4, 3 dtr, ch 4, sl st to fourth ch st at beginning.

Rnd 2: Ch 4, 7 tr in each of next 7 tr, ch 4, sc into next tr, ch 4; make 2 more groups of 8 tr, separated by ch 4, sc, ch 4, turn.

Rnd 3: 8 tr, ch 4, sc in sc, ch 4, make two more groups of 8 tr separated by ch 4, sc, ch 4.

This completes a shamrock. Make three more, always joining by two tips at first ch 4 of last rnd to the same point on shamrock previously made. Complete the first leaf of second shamrock motif, sl st to opposite point, ch 4, sc, ch 4, sl st to next point of next leaf. Complete other two leaves of shamrock. Last of four shamrock motifs in a square must be joined at four points.

An edge is worked around four shamrocks which make a square as follows:
Ch 8, dtr in middle dtr of stem, ch 2, dtr in same st, repeat at stem and at other side of leaf. Ch 8, sc in outer point of same leaf; ch 8, work a 2-dtr group between leaves; continue around in this manner to complete square.

To join adjacent squares, sl st the center of chains as they are made, to opposite chains.