Crochet Hook: K
Loosely chain 36.
Half Double Crochet (HDC) in the second chain from the hook and each one across (35 stitches). Chain 1 and turn.
HDC in each chain across. Chain 1 and turn. Repeat this row until you have 28 total rows completed, including the final Chain 1 and turn.
Single Crochet (SC) around entire blanket (on RS). Finish off and weave in all ends.
I've made six of them. They take about 60-90 minutes, depending on interruptions.
A close up view of the stitch.