wanted to get the notes down here before I forget:

1. cast on 21 stitches
2. K 9 ridges, or whatever you get in order to have 1⅜“, changing color every ridge
3. cast off in purl
4. carefully knot loose ends and trim to form fringed edge
5. block to rectangle
6. sew together as poncho shape
7. knot in extra yarn for fringe all the way around
8. if desired, wire brush fringe for extra fluffiness

(using the “wrong” side of the garter stitch gives a more elaborate colorwork effect)

This could also be made in a solid color, to avoid all the loose ends. I bet it could be made in mosaic knitting too…