I used 12 skeins of Country Green yarn, Lion Brand Jiffy for this project.

I worked this in 4dc mesh. In the linked pattern the black squares are open.

Start by chaining 153 (50 x 3 + 3 chains that act as first double crochet).

One open square is 1 double crochet, 2 chain and 1 double crochet, Two open squares together are 1 double crochet, 2 chain,1 double crochet, 2 chain and 1 double crochet.

One closed square is 4 double crochet, 2 closed squares together are 7 double crochet.