So I finished my blanket and began casting off when I realized I did not have enough yarn. What should I do? I hate to unravel 10 rows, but can I add another skein at the end of the blanket just to cast off?
Yes you can add another piece of yarn to finish the bind off. If you decide to not add more yarn you don’t have to undo the last 10 rows either, just the last one before you began the bind off; no one’s going to notice that it’s a row short.
If you have more yarn you are set. You don’t really have to undo anything except maybe a few stitches of the bind off so that you will have a nice tail to hide in. When you knit a stitch to do the next bind off stitch use the new skein and proceed as normal. Work in the ends to hide the evidence. You could try that and go ahead and work in the ends after a few more stitches. If somehow it doesn’t look good enough for you you can go clear back to the beginning of the row, but I don’t think you’ll have a problem.