Parasol Lace Pattern

Pattern
Cast on a multiple of 18 sts, plus 1.
Row 1 (RS): K1, *yarn over, K1 (P3, K1) 4 times, yarn over, K1; rep from * to end.
Row 2 and all WS rows: Purl.
Row 3: K1, *K1,yarn over, K1, (P3, K1) 4 times, yarn over, K2; rep from * to end.
Row 5: K1, *K2, yarn over, K1 (P3, K1) 4 times, yarn over, K3; rep from * to end.
Row 7: K1, *K3, yarn over, K1 (P2tog, P1, K1) 4 times, yarn over, K4; rep from * to end.
Row 9: K1, *K4, yarn over, K1 (P2tog, K1) 4 times, yarn over, K5; rep from * to end.
Row 11: K1, *K5, yarn over, K1 (S2KP, K1) twice, yarn over, K6; rep from * to end.
Rep Rows 1-12.