One of the most common mistakes for new knitters is accidentally adding new stitches by doing something called a yarn over. You may realize your number of stitches is growing because the edges of your knitting is slanting outward, or maybe you have been keeping track by counting your stitches every few rows. Another way to notice this problem is if you have mysterious holes in your knitting.
Take a look at this video by Sheep and Stitch. Davina shows how the accidental yarn over can happen, as well as how to notice the error on the very next row, and easily fix it by dropping that unwanted stitch.
Learning to spot mistakes on the next row is a very useful skill. So pay attention to your knitting. How does it normally look? React if something looks off. When you drop the accidental yarn over, your stitches around it may be looser than the rest of your work. This video by SoxTherapist shows you how to make the excess yarn disappear into the surrounding stitches after dropping the unwanted stitch.
If you don’t spot it on the next row, and you knit that new extra stitch, then the best approach is to unravel to the row before the mistake, then reknit. I know that it can be frustrating, but when the project is completed, you will be so happy you did it. This is the only way to completely fix a yarn over several rows down. Watch this video from Sheep and Stitch on how to unravel safely.
If you are too lazy to unravel and reknit and not too much of a perfectionist, there are other solutions. If you are still working on the piece, you can drop the stitches above the hole made by the yarn over, and use a crochet hook to twist the hole close, and knit the column of dropped stitches again. Note that this will leave you with an extra stitch, so you will need to make a decrease to get your stitch count down again. A simple decrease is knit two together (abbreviated k2tog) where you knit two stitches as if they are one. Alternatively, if you have already finished the piece, then you can sew the hole shot with a darning needle. Lucy Neatby demonstrates both methods in this video:
The good news is that you have discovered a new knitting stitch – the yarn over (abbreviated YO). It is an increase, i.e. a method for adding an extra stitch, that produces a pretty hole that can be used as a decorative feature. You often see yarn overs along the border or in lace work.
Extra stitches without holes
It is possible to acquire extra stitches without producing a hole. The first post in this video showed one example of how it can happen: By knitting into the thread between two stitches. This is a quite uncommon mistake. It’s more likely that you are adding the extra stitch when you turn the work and begin a new row. It is really important when you turn the work that the working yarn is pulled under the needle, and not over it. Watch this video by Joannes Web to see what happens.
Hopefully, I have answered any questions you had about extra stitches popping out of nowhere. Stay tuned for more content on beginner mistakes.