Increasing in seed stitch (and decreasing in seed stitch, too!)

Seed stitch (sometimes called moss stitch) is a stitch pattern which arranges knits and purls checkerboard-fashion so that every purl is surrounded by 4 knits, and every knit by 4 purls.

seed stitch arranges knits and purls checkerboard-fashion

Increasing and decreasing in a very regular stitch pattern like this is disruptive.

IMHO, the best little trick is to run a column of knits, increasing or decreasing along that line. Pushing the stitch pattern discontinuity up against a continuous column of knit stitches smooths and hides the irregularity.

Increasing seed stitch in circular knitting

Here is a schematic of what this would look like when knitting circularly, with the increase running along a single increase line, as it might be for a sleeve knit in the round.

circular knit seed stitch: increasing
along the center line, schematic

In the above schematic, the work is laid flat so you can see it, but in the real world, this sleeve will have been knit into a continuous spiral--a cone-shape, open at the bottom. In other words, for a circularly-knit sleeve, you would actually have knit this around and around, connected at the dotted lines. The continuous column of knits running down the schematic center is actually the sleeve underarm "seam." You have to use your imagination to "zip it shut" into a circle, along the red dotted lines.

Below is a photo of what an increase along a center line for an underarm looks like "in the wool."

circular knit seed stitch: increasing
along the center line, "in the wool"

How to make the increases

The little red loops stand for the increases, and you can use any kind of increases you like. One choice is e-loops slanting in different directions but most kinds of increases will give a good result: perhaps kfb (knit into the front and back) or the nearly invisible increase. Using a yo (yarn over) will result in holes, however, so that's not a great choice.

You need not worry whether the stitch to which the increase gives rise is ultimately going to be a knit or a purl. That's right--when you make the increases, you just make them however you like. Only on the FOLLOWING row do you have to worry about working that increased stitch as a knit or a purl, according to the checkerboard pattern established by the surrounding stitches. This is because a loop added to the fabric in the form of an added stitch does not take on the character of a knit or a purl until it is worked on the following row. If curious, here's more about this mystery of knitting. 

So the bottom line is, just make a pair of increases, and on the row or round after the increase, then work those new stitches as whatever they ought to be (whether knit or purl) as required to keep the checkerboard pattern going.

Increasing seed stitch in flat (back-and-forth) knitting

Above is about circular knitting. However, many patterns call for seed stitch to be worked flat (back-and-forth). Here is what the trick looks like when knitting flat and the increase is along the outer edges, instead of down the middle.

flat knit seed stitch: increasing
along the edges, schematic

Above is the schematic, and below is the final result "in the wool." The seam (red dotted lines) has not yet been sewn shut, and the sleeve is laying flat.

flat knit seed stitch: increasing
along the edges, "in the wool"

Rate of increase

In illustrating this post, I crammed lots of increases into a small sample, so the increases are worked every fourth row. However, an increase every 6th or 8th row is more common for a sleeve.  Yet though the rate may differ, the method remains the same. Just work your increases on either side of a center line (if working circular) or one stitch in from the edge line (if working back-and-forth), at the rate required.  Then, on the NEXT row, worry about whether the increased stitch should be worked as a knit or a purl, according to the seed stitch pattern established by the surrounding stitches.

Variation--more than one knit column separating increases

I've illustrated a single center column of knits, or a single column of knits along the fabric edge. Nothing stops you from from running two or three or more columns of knits, instead. In fact, if there will be seaming, remember that the edge stitches might be completely consumed, so an extra knit column along each outer edge might come in very handy. Consider ahead of time, and adjust the stitch count, if necessary,  to allow for the all-knit column(s) as well as to provide an odd or even number of stitches, as circumstances dictate, so that the stitch pattern is uninterrupted.

DEcreasing in seed stitch

All above relates to INCREASING in seed stitch, as might occur in a sleeve started at the bottom increasing from wrist diameter to shoulder diameter. Sometimes, however, you might be working the other way around, such as a sleeve started at the shoulder, and required to DECREASE to the wrist diameter as the sleeve is worked.

Luckily, DEcreasing in seed stitch is exactly the same theory, except that you simply work two stitches TOGETHER at the required rate, rather than form an increase. It is a nice touch to use a right leaning stitch like K2tog and the left leaning SYTK.

Once the excess stitch has been removed on either side of the center line, or on either edge of the row, continue to work the remaining stitches in checkerboard pattern as required by the surrounding stitches. Location of the decreases is the same as the location of the increases: if working circularly, one on either side of a center line of knits; if working back and forth, one decrease on each end of the indicated decrease row, one stitch in from the knit column(s) along each edge.

Does this look familiar?

When you get right down to it, this trick of shaping on either side of a column of knits is really just an adaptation of a method widely used in circular-knit raglan sweaters: if you have ever knit a raglan sweater in the round, this is the shaping which is done on either side of the 4 raglan seams, keeping the center column(s) in all-knits. The difference here is that the shaping (increasing or decreasing) is done in pattern of seed stitch, instead of stockinette, and the column(s) of stockinette disguises the stitch pattern discontinuity resulting from shaping.

--TK
You have been reading TECHknitting blog on increasing in seed stitch, and decreasing in seed stitch, too!