Quick fix: Seed stitch requires knitting over purls and purling over knits every row. If it looks like ribbing, you've been working the same stitch over itself. Tink back to a correct row and realign your knit-purl pattern.
What you are seeing
What should be a bumpy, checkerboard seed stitch texture instead looks like ribbing — smooth vertical columns of knits and purls. The fabric may still be stretchy but it doesn't have the flat, pebbly surface seed stitch should create.
Why it happens
- Working knit stitches over knit stitches and purl over purl — exactly what makes ribbing, not seed stitch
- Forgetting that in seed stitch you must always do the opposite of what is below you
- Starting a row with the wrong stitch after setting the work down
Fix it now
- Identify where the mistake started — look for the row where the texture changed from pebbly to vertical stripes.
- Tink back to just before that row.
- On the correction row, look at each stitch below: if you see a knit V, purl the stitch above it; if you see a purl bump, knit the stitch above it.
- Continue the pattern by always looking at the row below and doing the opposite.
- After 4–6 rows, check that the texture looks consistently bumpy, not striped.
Prevent it next time
- Use the mantra "knit the purls, purl the knits" — this is the entire rule for seed stitch.
- Mark the last stitch of each row with a locking marker — if the marker is on a knit, start the next row with a purl, and vice versa.