The cast-on is worked in the contrast color yarn. It doesn't matter if you use a single strand or long tail cast on, but the tail end of the yarn must be at the lower right corner when the first row is started. So, if you are using a long-tail cast-on, turn before introducing the main color; for a single strand cast-on, don't turn. This is actually what we do all the time without thinking about it, but here it really matters for having the contrast yarn in the correct position for Row 6.
Another change I made from the original was to make Rows 1 and 7 into stockinette rows, ie. knit on the right side or purl on the wrong side. Without this modification, we get running threads appearing as heavy horizontal bars at the bottoms of the clusters, as you can see in the photo to the right. In this instance, I found them distracting, hence the change. I did not change the selvedge stitches on these rows, though.
The fabric spreads, so the cast-on and bind-off must be very stretchy. There are any number of videos that show these techniques and/or, of course, you can always use larger needles.
Using a very elastic cast-on, cast on any number of stitches in contrast color (CC), adding 2 sts for side selvedges. Switch to main color (MC).
Row 1 (RS): P1, k until 1 st rem, p1.
Rows 2 and 4: Knit.
Rows 3 and 5: Purl.
Row 6 (RS): Slip work to other point of needle so that CC is available. Slip selvedge st. Using CC, (sl1 p-wise, knit up st in st 5 rows below slipped st, place the new st and the slipped st onto the LN and k them tog) until 1 st rem. Sl selvedge stitch.
Turn work. Switch back to MC.
Row 7 (WS): K1, p until 1 st rem, k1.
Rows 8 & 10: Purl.
Rows 9 & 11: Knit.
Row 12 (WS): Slip work to other point of needle so that CC is available. Slip selvedge st. Using CC, (purl up a st in st 5 rows below next st on needle, place the new st onto LN and p2tog with next MC st) until 1 st rem. Sl selvedge st. Turn work and switch back to MC.
Repeat from Row 1. Bind off very loosely in pattern on Row 6 or Row 12.
I've started swatching this pattern in novelty yarns and the results so far are exciting! I hope to have two or more swatches for the next post. Until then . . .