Crochet Hexagon Cardigan: Modern Joining Techniques

Introduction

There is a moment in most crocheters' lives when a garment stops feeling impossible. For a lot of us, that moment is the hexagon cardigan.

It looks complicated from a photo — the kind of project that gets saved and never started. It is not complicated. It is one motif, repeated six times, joined into something you can wear.

No armhole shaping. No sleeve cap to ease into a curve. No rows of increases calculated for a fitted shoulder. Just hexagons, a join, and a ribbed edge.

What separates a homemade-looking version from the cardigan you reach for every morning is the joining. That is where this guide spends most of its time.

Here is exactly what you need, in the order you need it.

What a Hexagon Cardigan Actually Is

A hexagon cardigan is a garment built from flat hexagonal motifs. Each hexagon is worked in the round from the centre out, with six corners and six straight sides.

The clever part is the fold. Fold a hexagon in half along a line running through two opposite corners, and the shape does something useful.

The fold line becomes your shoulder. Half the hexagon falls down the front, half falls down the back. The two remaining corners open into a natural armhole, which becomes your sleeve.

That is the whole trick. The garment shape is not drafted — it is folded.

The six-hexagon version takes it one step further. Two hexagons form the right front and sleeve. Two form the left front and sleeve. Two more form the back and its sleeves. Two lower panels extend the body below the underarm.

Six motifs. One repeated shape. A cardigan.

Why It Suits Beginners So Well

Most cardigan patterns ask a lot of a new crocheter. Shaping at the armhole. A sleeve cap that has to fit a specific opening. A neckline that has to sit flat.

Hexagon construction removes all three problems at once.

• No shaping. Every round is the same logic, just bigger. If you can crochet round three, you can crochet round six.
• No sleeve to attach. The sleeve is already part of the hexagon. You never sew a tube into an armhole.
• Forgiving fit. Because the fabric is built from flat motifs, small differences in tension read as texture, not as mistakes.
• Portable. A hexagon fits in a bag. You can finish a whole one at a swimming lesson.
• Fixable. If one motif goes wrong, you remake one motif, not a whole garment.

The one thing that does need attention is the join. A tidy join makes a beginner's cardigan look deliberate. A careless join makes an experienced crocheter's cardigan look homemade in the wrong way.

Yarn, Hook, and a Loose Gauge

Here is your supply list. Nothing on it is specialist.

• Yarn: worsted weight (CYC 4) or DK (CYC 3). A wool-acrylic or cotton-acrylic blend holds the hexagon shape best.
• Yardage: roughly 1,200–1,500 yards of worsted, or 1,400–1,700 yards of DK, for a cropped size M/L.
• Hook: 5.0 mm for worsted, 4.5–5.0 mm for DK. Go up to 5.5 mm if you know you crochet tightly.
• Notions: stitch markers, a blunt yarn needle, scissors.

Avoid 100% cotton for your first one. It is heavy, it stretches under its own weight, and it makes a cardigan that grows two inches by lunchtime.

Gauge matters here, but not in the usual way. You are not matching a stitch count — you are checking the size of one finished hexagon.

Work one hexagon through round four. Lay it flat and measure across from corner to corner. With worsted on a 5.0 mm hook it should be roughly 12 cm (4¾ in).

Smaller than that? Go up a hook size. Bigger? Go down. Two hook sizes either way is normal, and it is far easier to fix now than after six hexagons.

The Classic Hexagon Motif, Round by Round

This is the standard six-corner motif. Every round is built from groups of three double crochet, separated by chain spaces at the corners.

1. Round 1. Chain 4 and join with a slip stitch to form a ring. Chain 3 (counts as first double crochet), then 2 double crochet into the ring. Chain 2. Work [3 double crochet, chain 2] five more times into the ring. Join to the top of the starting chain. You now have six groups and six corner spaces.
2. Round 2. Slip stitch across to the first corner space. Chain 3, 2 double crochet, chain 2, 3 double crochet all into that same space. Chain 1. Work [3 double crochet, chain 2, 3 double crochet] into each remaining corner space, with chain 1 between groups. Join.
3. Round 3. Work a corner group into each corner space as before, then work 3 double crochet into each chain-1 space along the sides, with chain 1 between. Join.
4. Rounds 4 to 6. Repeat round 3. Each side gains one extra group per round.

That is the rule to remember: one more three-double-crochet group per side, per round. Round 3 has three groups per side. Round 6 has six.

Fasten off and leave a 20 cm tail. Do not weave it in yet — you may want it for joining.

How Six Hexagons Map to a Cardigan

Before you join anything, lay all six hexagons on the floor in the position they will be worn. This takes five minutes and saves an hour of unpicking.

Label them with safety pins or scraps of paper:

• Hexagons 1 and 2: right and left front, each with its sleeve.
• Hexagons 3 and 4: right and left back, each with its sleeve.
• Hexagons 5 and 6: lower body panels, sitting below the underarm.

Hexagon 1 joins to hexagon 3 along the right shoulder. Hexagon 2 joins to hexagon 4 along the left shoulder. The two pairs then meet at centre back and centre front.

Panels 5 and 6 fill in the lower body, joined along their top edges to the bottom edge of the upper hexagons.

Stand back and look at the layout before you commit. Check that all six motifs face the same way — with a variegated yarn, one flipped motif is very visible.

Joining Technique One: Join-As-You-Go

Join-as-you-go, usually shortened to JAYGO, is the modern default. You join in the final round of the second motif, so there is no sewing at all.

Finish hexagon one completely. Then work hexagon two to its final round, and change the method as you reach the shared edge.

1. Work the final round until you reach the first corner space on the joining side.
2. Chain 1, slip stitch into the matching corner space of the finished hexagon, then chain 1. Work your corner group into your own corner space as normal.
3. Work across the side. At each chain-1 space, chain 1, slip stitch into the corresponding space on the finished motif, chain 1, then work your group.
4. At the next corner, repeat the corner join. Carry on around the unjoined sides as normal.

The join disappears into the fabric. It is fast, it is strong, and it keeps the two motifs perfectly aligned because you are placing each stitch as you go.

One caution: JAYGO commits you. Check the placement of the motif before that final round, because unpicking a join is slower than sewing one.

Joining Technique Two: Mattress Stitch

Mattress stitch is the seam you use when you want the join to be invisible. It is sewing, not crochet, and it produces a flat, supple seam with no ridge on either side.

Thread a blunt yarn needle with the same yarn you crocheted with. Place the two hexagons right side up, side by side, edges touching but not overlapping.

1. Bring the needle up through the first stitch of the left motif, from back to front.
2. Cross to the corresponding stitch on the right motif, and go down from front to back.
3. Bring the needle back up one stitch along on the right, then across to the left.
4. Work in a figure-eight, always catching the bar under each stitch, never splitting the yarn.
5. After every three or four stitches, pull the working yarn gently snug.

Do not pull tight as you go. Mattress stitch closes the gap when you tension it at the end, and pulling early puckers the seam.

This is the slowest of the four methods and the tidiest. I use it for the centre-back seam, where a ridge would sit against the spine.

Joining Technique Three: Single Crochet Join

The single crochet join is the honest one. It leaves a visible ridge, and that is the point — it reads as a design line rather than a mistake.

Place the two hexagons wrong sides together, so the ridge sits on the outside of the garment.

1. Insert the hook through both layers at the first corner, and pull up a loop.
2. Chain 1, then work one single crochet through both layers at every stitch along the edge.
3. Keep your tension even. The join should measure the same length as the edges it is joining.
4. Slip stitch at the end, fasten off, and weave the tail into the seam.

For a flatter, subtler line, work through the back loops only on both motifs. The ridge shrinks by about half.

The single crochet join adds structure, which is why it works well on the shoulder seams and around a deep V neckline.

Watch the stitch count. One single crochet per stitch, every time. Two stitches worked into one space is the most common cause of a wavy seam.

Joining Technique Four: Zig-Zag Slip Stitch

This is the join that keeps hexagon points crisp. A hexagon edge is not straight — it steps up and down. Most seams blunt those points. This one does not.

Hold the motifs right sides together and work a slip stitch seam that follows the stepped edge exactly.

1. Join yarn at the outer corner of the first motif with a slip stitch.
2. Slip stitch through both layers along the edge, one stitch per stitch.
3. At a corner point, work the slip stitch into the chain-2 corner space itself, not into the stitch beside it.
4. Where the edge steps in, step with it. Do not bridge across the notch with a long stitch.
5. Continue to the end, then fasten off and weave the tail along the seam.

The result is a fine, flat line that traces the geometry of the motif instead of fighting it. Points stay pointed, and the zig-zag reads as intentional.

Slip stitch joins use very little yarn, so keep the tension light or the seam will pull the fabric in.

Keeping Corners Aligned So Seams Sit Straight

Almost every crooked hexagon cardigan is a counting problem, not a tension problem.

• Mark every corner before you join. Six markers, six corners. Remove them as you reach them.
• Join point to point. A corner space always meets a corner space. If a corner lands halfway along a side, stop and recount.
• Count groups, not stitches. Round 6 should have six three-double-crochet groups on every side. Verify before joining.
• Work both motifs from the same side. Start every join at the same corner so the step pattern matches.
• Pin, then join. Lay the pieces flat and pin the corners. Pinning takes two minutes and prevents a twisted seam.

If two edges are different lengths, do not stretch the shorter one to fit. Find the extra group and remove it. A seam that is forced will pull the whole garment out of shape.

Adding a Ribbed Border and Cuffs

The border is what turns six motifs into a cardigan. It also hides the small untidiness at the front opening.

Use a hook one size smaller than your body hook — 4.5 mm if you crocheted the body on 5.0 mm. This draws the edge in and stops it flaring.

1. Join yarn at the bottom right front corner.
2. Work one round of half double crochet evenly around the entire opening: up the right front, around the back neck, down the left front.
3. On the next round, work half double crochet in the back loop only. This creates the ribbed texture.
4. Repeat that round four to six times, or until the border is as wide as you want it.

For the cuffs, join yarn at the underarm and work half double crochet in the back loop only in continuous rounds until the cuff measures 6–8 cm. Decrease by working two together every eighth stitch on the last two rounds.

Add buttonholes on the right front band if you want a closure. Chain 2, skip 2 stitches, and space them every 8 cm.

Sizing Adjustments Without Starting Over

Hexagon cardigans are unusually easy to resize, because size is controlled by rounds rather than by pattern drafting.

• Bigger body: add one round to all six hexagons. Each round adds roughly 4–5 cm across the motif, which adds about 8–10 cm to the body circumference.
• Smaller body: stop one round earlier on all six. Keep them consistent — a mixed set will not join.
• Longer sleeves: after joining, work extra rounds of double crochet around the sleeve opening until it reaches your wrist.
• Shorter sleeves: stop the sleeve rounds at three-quarter length and add a deeper cuff.
• Longer body: add rounds to the two lower panels only, or work a few rows of half double crochet along the hem before the border.

Write down the round count of your first hexagon before you make the second one. Six motifs made to two different counts will not sit flat together, and the fix is remaking rather than adjusting.

Weaving In Ends and Blocking

Weave in every tail as you finish each hexagon. Leaving twelve tails to the end is the reason half-finished cardigans live in bags.

Thread each tail onto a blunt needle and run it through the wrong side of the fabric for 5–8 cm, changing direction once. Do not knot. Change direction and the tail will not work loose in the wash.

Blocking matters more than usual here, because the hexagon points need to be persuaded into shape before joining.

1. Soak the motifs in cool water for 15 minutes.
2. Squeeze gently — never wring — and roll in a towel to remove excess water.
3. Pin each hexagon to a towel or blocking mat, stretching the points out evenly.
4. Measure corner to corner and pin every motif to the same measurement.
5. Leave to dry completely, usually overnight.

Blocked motifs are the same size, and same-size motifs join straight. This single step prevents most of the problems in the next section.

Troubleshooting: Wavy Joins, Gaps, and Mismatched Hexagons

The join waves. You have worked too many stitches into the seam. One stitch per stitch, no exceptions. Undo the seam and recount rather than trying to block it out — a wavy seam will always come back.

Gaps at the corners. You joined into the chain-1 space beside the corner instead of the chain-2 corner space. The corner needs the full chain-2 to turn cleanly. Rip back to the corner and rejoin there.

One hexagon is bigger than the others. Usually a hook change or a tighter final round. Block the odd one to match the others first. If it still will not match, place it at the underarm or the lower panel, where a slight difference is hidden.

The front edges do not meet. One hexagon is upside down. Check that all six were started from the same corner before you join anything else.

The shoulders pull. Mattress stitch was pulled too tight. Ease the seam out with your fingers and re-tension the whole seam, not just the tight section.

None of these are serious. Every one is fixable in under twenty minutes, and every one is easier to spot on a blocked, flat motif than on a finished garment.

A Short Closing Encouragement

Your first hexagon cardigan will not be perfect. The seams will be a little uneven somewhere, and one sleeve will sit slightly differently from the other.

Wear it anyway. That is what the second one is for.

Start with six hexagons in a yarn you love, join them with the method that suits your patience that week, and add the border last. The construction does the hard work for you.

You already know how to crochet a hexagon. The only new skill is the join — and now you have four of them.

If you enjoyed this project, you might also like our guide to Bavarian Crochet: Textured Squares Step by Step.