One row of chain. Second row single crochet two chain , skip two chain from previous row and single crochet into the fourth chain continue to the end. Third row start with three chain in the first single crochet from the previous row. Then continue along the row with basic three double crochet as per granny squares in the three chain space. End with one double crochet into the final single crochet in previous row. Repeat these two rows until desired length is reached.