How to Crochet the Clamshell Stitch With Easy Photos and Video

Updated: 21 October 2026 by Sylwia (MyCrochetory)

The clamshell crochet stitch turns plain stripes into rows of little seashells. Each row ends in soft scallops, and the next color dips right down into them, so the fabric looks wavy and bold at the same time.

I learned this stitch for one reason, I wanted the scalloped look I’d seen in a knitting pattern. When I made my Clamshell Shawl, I photographed every single step, and that’s how this tutorial came together, with a video, a chart and photos for each row.

Short on time? Jump straight to the step-by-step photo tutorial.

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What Is the Clamshell Crochet Stitch?

The clamshell crochet stitch, also called the clam stitch or clam shell stitch, builds a row of fans out of slip stitches, half double crochet and double crochet. Between the fans you get little dips, so the top edge of every row moves like a wave.

The real star is the Clamshell Spike. It’s three long double crochets that reach down into the rows below and fill each dip with the new color, and that’s where the shell shape comes from.

From a Knitting Pattern to My Clamshell Shawl

It all started with a knitting pattern. I saw those scallops, wanted them in my crochet and went hunting for a stitch that could do the same thing, and when I spotted the clamshell stitch, it was exactly what I needed.

So it went straight into my Clamshell Shawl, four colors of scallops on a triangle shawl. Later it came back in the Clamshell Square Blanket, and both patterns are free on the blog if you want to use your new stitch right away.

Is the Clamshell Crochet Stitch Hard?

Those scallops come from basic stitches only. Chain, slip stitch, single crochet, half double crochet and double crochet are all you need for the clamshell crochet stitch.

The one new move is the spike. Because you work it down into rows you’ve already made, the trick is to pull each double crochet up to the same height and to look closely at where your hook goes.

That’s why I took a photo for every part of the spike. Count to eight, follow the pictures, and by the second stripe you won’t need to look at them as often.

The sides of your work need a bit of attention too, because some rows start with slip stitches and others with a chain 3. If the edges start to look uneven, my tutorial on how to crochet straight edges every time shows how to keep them straight from the first stripe to the last.

Colors and Yarn for the Clamshell Crochet Stitch

You switch colors every three rows, so the clamshell crochet stitch is a great way to use up leftover yarn. Each new stripe of fans sits on the last one, and the spikes drag a little of the new color down into the old one. To keep all those color changes neat, my guide on how to join yarn ends shows four easy ways to add a new color.

For my swatch I went with mustard, gray, black and cream. Strong contrast helps a lot here, because the scallops only really show when the stripes are clearly different.

Trying it for the first time? Start with a smooth yarn in a light color so you can see every stitch, and keep the dark colors for later, once the spike feels easy.

Want to try it later? Save the clamshell crochet stitch on Pinterest so it’s there when you have a free evening.

Clamshell Crochet Stitch Video Tutorial

Prefer watching? Here’s the clamshell crochet stitch video, and the written steps with photos are right below it.

TIP: To view this clamshell crochet stitch video tutorial properly, please disable any ad-blocker you have running.

Clamshell Crochet Stitch Photo Tutorial, Step by Step

This tutorial uses American crochet terms.

Here’s the stitch chart for one repeat, in case you like to read charts as you go.

Using your first color of yarn, work a starting chain in multiples of 8 plus 2. For this tutorial I used 34 chains.

Row 1

Work first single crochet in the second chain from the hook, and then work one single crochet in each chain across to the end. Turn your work.

Row 2

Chain 1 (turning chain, do not count as a stitch). Work single crochet in each stitch across to the end. Turn your work.

Row 3

Do not work a turning chain. Work slip stitch into the first two stitches. Then, work one half double crochet in the next stitch, double crochet in the next 3 stitches and half double crochet in the next stitch. Then slip stitch the next three stitches. After these stitches the pattern will repeat as you do 1 half double crochet, 3 double crochets, 1 half double crochet and 3 slip stitches. Continue this pattern until the end of the row, which finishes with one slip stitch into the last two stitches. At this point, you should change the color of your yarn. Turn your work.

SLST – slip stitch, HDC – half double crochet, DC – double crochet.

Row 4

Chain 3 (counts as a double crochet). Work another double crochet in the next stitch, 1 half double crochet in the next stitch, single crochet in the next 3 stitches and then another half double crochet in the next stitch.

Next, we are going to make a Clamshell Spike. To make this skip the first slip stitch and work double crochet one row below the next slip stitch (into the single crochet of row 2 under this second slip stitch). The hook points at the right place.

Then, work a second double crochet right below your last double crochet – into the single crochet two rows below. The hook points at the right place. Make sure that your both double crochets have the same height.

To work the third double crochet of the Clamshell Spike, you have to put this stitch into exactly the same stitch that the first double crochet was placed. The hook points at the right place. Make sure your yarn does not cross at the back.

And now your Clamshell Spike is done!

After the Clamshell Spike you have to skip the next slip stitch and work one half double crochet in the next stitch. Then, work 3 single crochets and 1 half double crochet.

It’s time for another Clamshell Spike, and then again 1 half double crochet, 3 single crochets and 1 half double crochet. Continue this pattern until the end of the row, which finishes with a double crochet in each of the last two stitches. Turn your work.

Row 5

Chain 1 (turning chain, do not count as a stitch). Work single crochet in each stitch across to the end. Turn your work.

Row 6

Chain 3 (counts as a double crochet). Work another double crochet in the next stitch. Then, work one half double crochet in the next stitch, slip stitch in the next 3 stitches and half double crochet in the next stitch. Then double crochet the next three stitches. After these stitches the pattern will repeat as you do 1 half double crochet, 3 slip stitches, 1 half double crochet and 3 double crochets. Continue this pattern until the end of the row, which finishes with a double crochet in each of the last two stitches. At this point, change the color of your yarn and turn your work.

Row 7

Chain 1 (turning chain, do not count as a stitch). Single crochet in each of the first 2 stitches. Then, work one half double crochet. Now it’s time for a Clamshell Spike, just like we did before. Skip the first slip stitch and work a double crochet into the single crochet (Row 5) below the second slip stitch. Then work a double crochet into the single crochet two rows below (Row 4) right below the first double crochet you just made. Then work the last double crochet into the same place as the first double crochet was made (into the single crochet of Row 5 below the second slip stitch). The Clamshell Spike is now done.

After the Clamshell Spike you have to skip the next slip stitch and work one half double crochet in the next stitch. Then, work 3 single crochets and 1 half double crochet.

It’s time for another Clamshell Spike, and then again 1 half double crochet, 3 single crochets and 1 half double crochet. Continue this pattern until the end of the row, which finishes with a single crochet in each of the last two stitches. Turn your work.

Row 8

Chain 1 (turning chain, do not count as a stitch). Work single crochet in each stitch across to the end. Turn your work.

Next, repeat instruction for Row 3 – Row 8, changing the colors every three rows.

Stuck on a spike? Ask in my Facebook Group or Ravelry Group, or email me at mycrochetory@gmail.com.

Made a clamshell swatch or project? Share it on Instagram with #mycrochetory and tag @mycrochetory so I can see it.

More Crochet Stitch Tutorials

Once the clamshell spike clicks, try one of these next. They all add texture with basic stitches, and each one has its own step-by-step photos.

• V-Stitch, two double crochets with a chain between them, light and quick to grow.
• Star Stitch, little stars made by pulling up five loops at once.
• Herringbone Stitch, a zigzag single crochet texture with a 2-row repeat.
• Moss Stitch, single crochet and chain 1 for a flat, woven-looking fabric.

Looking for even more ideas? My list of 40+ creative crochet stitches collects textures from all over the crochet community.

Clamshell Crochet Stitch FAQ

How many chains do I need for the clamshell crochet stitch?

Chain a multiple of 8 plus 2. I used 34 chains for my swatch, and you can add 8 chains for every extra fan.

Why are my clamshell spikes different heights?

The three double crochets of the spike go into different rows, so it’s easy to make one too short. Pull each loop up to the height of the row you’re working on before you finish the stitch.

Why does yarn show at the back of my spike?

The third double crochet goes into the same stitch as the first one, and the yarn can get caught behind the spike. Check the back before you move on, and if the yarn crosses there, undo that stitch and work it again.

What is the difference between the clamshell stitch and the shell stitch?

A classic shell stitch puts several double crochets into one stitch. The clamshell crochet stitch mixes slip stitches, half double crochet and double crochet in a row, and adds the spikes that reach down into earlier rows.