It is a bit different in the way that we make an intarsia diagonal design in garter stitch. I had tried the methods which I applied on the intarsia vertical in garter stitch but I couldn't get a neat and clean looking diagonal intarsia. I won't say that they are not nice because those methods would create small bars on the line that look nice at the both sides of the knitting pieces respectively. I take it as a unique pattern for an intarsia design in garter stitch.
Anyway, I use another method to create a nice and neat looking diagonal color blocks which without showing any bars at the right side of the work. With this method, I don't increase color in every row. I will only increase one color every time I knit at the right side of the work. This is a non-reversible knitting work, therefore we have to make sure of the both right and wrong sides when knitting because the way we change colors on each side of the work would be different.
Right diagonal
2. Turn your work to the wrong side. Knit the first stitch. Hold the tail of the light green yarn with your left hand when you knit the first stitch. Then, gently pull the running yarn to snug up the stitch on the right needle.
3. Then, bring the light green yarn to the front between the two needles. Drop the light green yarn at the front, pick up the dark green yarn (this way the two yarns will be twisted) and bring the dark green yarn to the back. Knit to the end of the row with the dark green yarn.
4. & 5. Turn your work to the right side. Knit to the part where you have one dark green stitch left on the left needle. Now, insert the right needle into the dark green stitch and then pick up the light green yarn from under the dark green yarn. Knit to the end of the row with the light green yarn. Here you have increased one color. By referring photo no. 5 you can see the second last stitch - a light green stitch is above the dark green stitch, this is the added color. You have to increase one light green color every time you knit at the right side, so the light green will be increased gradually to create a left diagonal intarsia design.
6. Turn your work to the wrong side. Knit to the color changing point and repeat the step 3 to 5. Photo no. 6 is the sample of right diagonal intarsia.
Left diagonal
2. Pick up the dark green yarn from under the light green yarn. Knit to the end of the row with the dark green yarn.
3. Turn your work to the wrong side. Knit to the color changing point (the stitch before the light green yarn). Bring the dark green yarn to the front between the two needles and drop it at the front. Pick up the light green yarn from under the dark green yarn (this way the two yarns will be twisted) and bring it between the two needles to the back of the work. Knit to the end with the light green yarn.
4. Turn back to the right side. Knit the light green stitch/stitches. When you meet the first dark green stitch on the left needle, knit this stitch with the light green yarn in order to increase one light green stitch. You have to increase one light green color every time you knit at the right side, so the light green will be increased gradually to create a left diagonal intarsia design.
5. Now, drop the light green yarn and pick up the dark green yarn from under the light green yarn. Knit to the end of the row with the dark green yarn. Then repeat step 3 to 4.
6. Done.
Right diagonal Left diagonal
