How do I fix a fallen hem?

The invisible slip stitch, when hemming tape is acceptable, and getting the length right before you sew.

Difficulty: beginner
Time: 30 min
Read: 3 min

Short answer

Pin it at the original fold line, then use a slip stitch that catches only a thread or two of the outer fabric so nothing shows. Hemming tape works for a quick fix but does not survive many washes.

A fallen hem is usually one broken thread that unravelled. Restitching it invisibly is a fifteen-minute job with one technique.

What you'll need

Needle and matching thread
Pins and an iron
Hemming tape, for a temporary fix

Step by step

Work out how much has come down.Sometimes a few centimetres, sometimes the whole hem. Check the rest of the hem for weak stitching while you are there.
Press the fold back into place.The original crease is your guide. An iron restores it and holds the fold while you pin, which makes the repair far easier and more accurate.
Pin from the inside.Pins perpendicular to the hem edge, every few centimetres. Check the length hangs evenly by trying the garment on before sewing.
Match the thread carefully.In daylight, against the fabric. A slightly darker thread is less visible than a slightly lighter one.
Use a slip stitch.Bring the needle through the hem fold, then catch just one or two threads of the outer fabric, then back into the fold. Nothing shows on the right side, which is the whole point.
Keep the tension loose.Pulled tight the stitches dimple the outer fabric and show as a line of puckers. The thread should lie in the fabric rather than pulling it.
Space the stitches about a centimetre apart.Closer is stronger but more visible and slower. A centimetre is the usual compromise on ordinary garments.
Secure both ends properly.Several small stitches within the fold at each end, overlapping the sound original stitching so it cannot unravel again from that point.
Press it when finished.It settles the stitches into the fabric and makes the repair much less visible.
Use hemming tape only as a stopgap.Iron-on tape is quick and works for an evening, but it stiffens the hem and fails after a few washes. It is not a repair.

Tips

Press the original fold back first. It gives you an exact guide and holds the hem while you pin.
Catch only one or two threads of the outer fabric. That is what makes the stitch invisible.
Slightly darker thread is less noticeable than slightly lighter.

Common mistakes

Pulling the stitches tight — It dimples the outer fabric and produces a visible line of puckers along the hem, which is more obvious than the fallen hem was.
Relying on iron-on hemming tape — It stiffens the hem and separates after a few washes. It is fine for an emergency before an event but it is not a repair.

If it doesn't work

Stitches visible on the outside

Cause: Catching too much fabric — Fix: Take only one or two threads of the outer cloth with each stitch.

Hem puckered

Cause: Thread pulled too tight — Fix: Unpick and resew with the thread lying loosely.

Hem uneven

Cause: Not pinned to the original fold, or not checked hanging — Fix: Press the original crease back and try the garment on before sewing.

Hem came down again

Cause: Ends not secured into sound stitching — Fix: Overlap the existing intact stitching by a few centimetres at each end.

Questions people ask

What stitch should I use for a hem?

A slip stitch or blind hem stitch, which passes through the hem fold and catches only one or two threads of the outer fabric so nothing shows on the right side.

Is hemming tape any good?

As an emergency fix before an event, yes. As a repair, no — it stiffens the fabric and comes apart after a few washes.