🧩 Guide · Joining

How to Join Granny Squares: 4 Easy Methods for Bags and Blankets

Joining is the magic moment when a pile of squares becomes a bag, a blanket or a cushion. You only need four methods, and all of them are beginner friendly. Here is how each one works, and which is strongest for a granny square bag.

⚡ Quick answer: for a bag, use a slip stitch or single crochet seam through the back loops. For a soft blanket, use join-as-you-go or a whip stitch.

Before You Start Joining

• Weave in every end first. It is much fiddlier once the squares are joined.
• Check the squares match. Measure them and block lightly if needed, so the edges line up.
• Lay out your design on a table or the floor, so each color lands where you want it.
• Join with the same yarn and hook you used for the squares, or a matching color.

Method 1: Slip Stitch Seam (Best for Bags)

The most popular join: quick, flat and strong, which is exactly what a tote bag needs.

1. Hold two squares together: right sides together to hide the seam inside, or wrong sides together for a decorative ridge on the outside.
2. Put your hook into the corner of both squares, through the back loop only of each stitch.
3. Yarn over and pull through everything on the hook. That is one slip stitch.
4. Repeat all along the edge, then fasten off and weave in the end.

💡 Keep your slip stitches loose. A tight seam puckers and makes the squares curl.

Method 2: Single Crochet Seam (Strongest)

Just like the slip stitch seam, but with a single crochet (US terms; a UK double crochet) in each pair of stitches. You get a raised ridge and extra strength, ideal for a tote bag that carries books or shopping.

1. Hold two squares right sides together for a hidden seam.
2. Insert your hook through the back loops of both squares at the corner.
3. Yarn over, pull up a loop, yarn over and pull through both loops.
4. Work one single crochet in each pair of stitches across the edge.

Method 3: Whip Stitch (Flattest Join)

Sewn with a tapestry needle, the whip stitch gives an almost invisible seam. Lovely for light blankets, baby blankets and clothes.

1. Lay two squares side by side, right sides up.
2. Thread a tapestry needle with a long piece of yarn.
3. Go through the back loop of a stitch on one square, then the matching back loop on the other.
4. Pull through and repeat along the edge with even tension.

Method 4: Join-as-You-Go (No Sewing)

With join-as-you-go (JAYGO), each new square attaches to its neighbors while you crochet its last round. No seaming at the end!

1. Crochet your second square up to the last round.
2. At the first corner, ch 1, slip stitch into the corner space of the finished square, then ch 1.
3. Along the side, work each 3 dc cluster, then slip stitch into the matching ch-1 space of the finished square.
4. Join the next corner the same way and finish the round as normal.

JAYGO is perfect for blankets. For bags it is a little softer than a back-loop seam, so most makers choose method 1 or 2.

Which Method Should You Choose?

Join in Rows, Then Join the Rows

Do not join squares in random order. Join them into strips first, then join the strips together. Every seam stays straight.

No holes at the corners: where four squares meet, carry the seam straight across the point so the joins cross like a plus sign. Pull snug and keep the same tension on every seam.

Joining Squares for a Crochet Bag

• Pick cotton yarn. It does not stretch, so seams stay firm under weight.
• Use a back-loop slip stitch or single crochet seam for a strong, flat join.
• Join right sides together on the sides and bottom, so the seam hides inside.
• Reinforce the top corners where handles attach, with an extra round of single crochet.

Common Joining Mistakes

• Joining too tight: the seam puckers. Use the same hook, or one size up.
• Uneven squares: block them to the same size first to avoid gaps.
• Mixed seam sides: keep all seams on the same side so the ridges match.
• Skipped stitches: count both edges so every pair matches.

Joining Granny Squares: FAQ