Using the Apple Blossom yarn, cast on 100 sts and distribute them onto four needles, 25 sts each. The beginning of the round is between needles I and IV. Begin the lace pattern from row 1 of chart I. Work the 5 st pattern repeat 20 times. Work rows 2–4. Now repeat rows 1–4 another 3 times.
Join the off-white yarn and knit 1 round. Continue in stockinette st. On the first round, decrease 1 st on each needle = 96 sts.
When the piece measures 7 cm, begin the colourwork pattern on row 1 of chart II. Work the 96 st pattern. Work rows 2–68 of chart II.
1 st decreased at the beginning and end of rows 26, 32, 38, 44, 50, 56, 62 and 68. 80 sts on the needles after the decreases.
Continue working stockinette st with the off-white yarn, decreasing as instructed. Decrease round: skp at the beginning of needles I and II, k2tog at the end of needles III and IV = 76 sts. Work 1 round even. Work another decrease round = 72 sts. Work 2 rounds even.. Repeat the decreases = 68 sts. Work 3 rounds even.. Work the decreases on needles I and IV only = 66 sts. Work 3 rounds even.. Work the decreases on needles I and IV only = 64 sts. Knit 2 rounds. The piece now measures approx. 34 cm.
Redistribute the sts so you have 16 sts on each needle.
Begin the heel flap: using Apple Blossom, knit the sts on needle I onto needle IV = 32 sts. Leave the other sts on hold and turn work.
Begin the reinforced st pattern:
Row 1: (RS) *slip 1 st (yarn in back), k1*, repeat *–* to end of row. Turn work.
Row 2: (WS) slip 1 st (yarn in back), purl to end of row. Turn work.
Repeat rows 1–2 a total of 16 times (= 32 rows).
Continue the reinforced st pattern as established and begin turning the heel: work until 11 sts remain at the left end of the heel flap. Work the skp decrease (= slip 1 st knitwise, k1, pass the slipped st over) and turn work. Slip 1, p10, p2tog. Turn work. Slip 1 st, work until 10 sts remain, skp. Continue in the same manner, decreasing sts at the sides with 12 sts in the middle. When only the middle sts remain, distribute the heel flap sts onto two needles, 6 sts each. K6 to move the yarn between needles IV and I. Use the off-white for the rest of the sock.
Pick up onto needle I 16 sts from the left edge of the heel flap + 1 st from between the needles. Knit the 6 heel flap sts and knit the picked-up sts through the back loop. Knit the sts on needles II and III. Pick up 16 sts from the right edge of the heel flap + 1 st from between the needles. Knit the picked-up sts through the back loop onto needle IV.
Continue working stockinette st with these 78 sts and begin the gusset decreases: k2tog at the end of needle I, skp at the beginning of needle IV. Repeat the decreases on every 2nd round until 16 sts remain on each needle.
Keep working stockinette st until the sole measures 19 cm or until the sock covers your fifth toe.
Begin the toe decreases: k2tog, k1 at the end of needles I and III, and k1, skp at the beginning of needles II and IV. Work the decreases on every 4th round 2 more times and then on every 2nd round until 7 sts remain on each needle. Then work the decreases on every round. When 8 sts remain in total, break the yarn, pull it through the sts and securely weave in.
Knit the other sock to match.
Lightly steam the socks.