Introducing the Mermaid Shells Blanket. This giant granny square baby blanket is quick and easy to make and the colour combination is just stunning. I’ve finished this blanket with a shell style border to give those sea side mermaid vibes.
Granny squares are iconic and never seem to go out of fashion and it’s easy to see why. These versatile squares can be adapted to suit your own colour preferences and are quick and easy to work up. Personally, I’ve made countless granny square blankets and just can’t get enough of them.


Table of contents
- Granny Square Blankets
- How many Granny Squares do I need for a blanket?
- What makes the perfect Granny Square?
- Materials & Tools
- Colour Combinations
- Pattern Notes
- Sizing
- Gauge Swatch
- Gauge
- Crochet Terms & Abbreviations
- Pin For Later
- Fast & Easy Blanket Patterns
- Video Tutorial
- Ways to get this pattern
- Mermaid Shells Blanket: FREE Pattern

Granny Square Blankets
There are endless possibilities when it comes to granny square blankets. You can take a basic granny square pattern and make changes to colour ways, amount of rounds and layouts and create something unique each time. They’re one of my favourite things to crochet.
How many Granny Squares do I need for a blanket?
Well, for this blanket…JUST ONE! We’re going to be making a giant crochet granny square (Also known as an infinity granny square). This makes this pattern so easily adaptable because you can keep adding your rounds to make your blanket as big or small you like!
What makes the perfect Granny Square?
Honestly, what makes the perfect granny square is really down to personal preference. In my basic granny square tutorial created for complete beginners, I chain 3 in the corners and chain 1 between granny sets. I find this a great way of helping beginners understand the concepts of a granny square. In this pattern however, I have only chained 2 in the corners and didn’t chain at all between granny sets. I wanted to created a tighter looking square so this worked perfectly for me. I highly recommend experimenting with this and seeing what you preference is.
Materials & Tools
- Yarn: Caron Simply Soft in:
- Colour A: Off White
- Colour B: Robins Egg
- Colour C: Orchid
- Colour D: Watermelon
- Colour E: Soft Green
- Crochet Hook: 5mm (US H-8)
- Darning needle/Tapestry needle
- Scissors
Colour Combinations
I’ve chosen to use pastels with a pop of colour for my Mermaid Shells Blanket which I think looks stunning, but here’s a few more colour ways to give you some inspiration.




Pattern Notes
Written in UK terms but switchable to US terms below. When you work three trebles (US Doubles) into one space, it will be referred to as a granny set. The beginning magic ring can be replaced with a chain 4 and join in first chain with a slip stitch if preferred.
Sizing
Completed size: This baby blanket measures 68.5cm (27inch) Square.
Gauge Swatch
Crochet gauge (Also know as tension swatch) is important because it ensures that your finished projects have the correct size, fit, appearance, and use of materials as intended by the pattern designer. Ignoring gauge can lead to the project not coming out to the intended size.
I highly recommend making a gauge swatch to ensure you are not disappointed with the finished item.
If you’re struggling to hit gauge, you may find the following video helpful. In this video, I explain how to adjust the amount of stitches in your own and also demonstrate how to adjust the height of your stitches using the golden loop. This is a great way to get to know your own personal tension and I’d highly recommend watching this video tutorial.
Gauge
Your square should measure 10cm X 10cm (4inch X 4inch) after 4 rounds.

Convert Pattern Terms
Here you can quickly switch between UK and US crochet terms. This will make following the pattern easier as all terms will be converted to your preferred version.
Crochet Terms & Abbreviations
- Chain Stitch (ch): Insert hook, yarn over, pull though loop on the hook.
- Slip Stitch (sl st): Insert hook through stitch, yarn over, pull through chain and loop on the hook.
- Double Crochet(s): dc(s): Insert hook into stitch, yarn over, pull up a loop, you will have two loops on the hook. Yarn over, pull through remaining two loops.
- Treble Crochet(s): tr(s): Yarn over, insert into chain space, yarn over, pull through, you will have three loops on the hook. Yarn over, pull through two loops, yarn over, pull through remaining two loops.

Unsure of the differences between UK and US terms? Need a refresher on how to do your stitches? In my ‘How to crochet: A handy reference guide’ EBook I help you with all of these terms and you can always have them to hand! You will also get exclusive access to free video instructions. Learn more about the eBook here.
Pin For Later


Fast & Easy Blanket Patterns
Do you love crocheting fast and easy blankets? Check out these patterns available on the blog:



Pattern Support
The fastest way to get pattern support is to ask in our dedicated facebook group for Bella Coco Crochet patterns. This is the best place for you to connect with other crocheters.
Please note, if you wish to change and adapt this pattern in any way, this must be done at your own exploration and we cannot offer assistance with this.
Video Tutorial
The video for this pattern explains how to work the first 4 rounds of this project as well as how to change colours in your work. The video also shows you how to add the boarder to complete the blanket.
Remember the video uses UK terms, but we do make reference to the US terms to help you out if needed.
If you are confident in making granny squares, I’d highly recommend watching my video on the no sew granny square.


Ways to get this pattern
This pattern is available here for FREE on the blog. Simply sign in to your Grow account to get access to the pattern. You can upgrade the beautiful Ad-Free PDF with all of the information for this pattern plus step-by-step photos, a chart and a left-handed resource via my Etsy shop, Ravelry and Bellacococrochet.com
This beautiful PDF pattern includes additional information such as yarn substitutions, charts and step by step photos for completing each stage of the project.
Remember, if you are part of The Crochet Community, you get this pattern as part of your membership!
Mermaid Shells Blanket: FREE Pattern

Foundation: With Colour A, make a magic ring.
Border
You are viewing this pattern in UK terms.
Ss across to the next tr so you are starting in the centre tr on the first corner granny set.
Ch-3, work 3 tr in same st, miss a st, ss in ch-2 sp. *Miss next st, 4 tr in next st, miss a st, ss in sp between granny set or ch-2 sp; rep from * around. Ss in top of ch-3. Fasten off.
Sew in all ends.
I always love to see your makes so if you try any of my patterns or follow my stitch tutorials please tag me @bellacococrochet or use the #bellacococrochet
sarah-jayne
Although I am not a beginner, I do think this would be a brilliant first project for a beginner. This is easy to make and the first time I have turned my granny squares. Had the urge to make a granny square this afternoon. I think I needed to have a break from my more complex projects and I absolutely loved making this with my left over yarn! Thanks SJ. X
Hi Katie you are very welcome 🙂