While discussing double knitting, I looked at the Hoover blanket pattern and am quite sure it’s not correct for the single color, single yarn technique. To accomplish that type of double knitting, you need to make 4 passes of the double knit center to every two passes of the single fabric edges. This creates two completed rows of each (because the slipped sts of the double knit cause that fabric to require two passes to complete one row).

Swatch #1 with loopy borders hanging down* were done as written in the pattern (2 passes for all). The one that has the edges straight across (swatch #2) has 4 passes in the center, 2 on thevsides. The drawing on yellow paper (photo #2) shows the concept. I say to myself, “Two to the center, two to the ends.” And I keep a row count - you can easily lose track of which pass you were on.

Explained in June Hemmons Hiatt’s “Principles of Knitting” regarding double knit pockets. P. 330 on my new-ish printing of the book. She also recommends a smaller needle for the double knit portion in the center (double knits are always looser). I did not do that on these swatches.

Maybe you’re still going to occasionally need to add the extra garter stitch border rows recommended in the pattern (unless you’ve used a smaller needle for the double knit portion). I haven’t made a large enough swatch to determine that.

The 3rd photo shows some progress, & confirms it would be better with a smaller needle used for the center. (#4 is a hotpad made from the swatch eventually.)

Hoover Blanket is here or here.

*Those sides will become droopier and droopier as you continue adding rows.