Rainbow Edged Granny Blanket Crochet Free Pattern
There is something undeniably magical about picking up a crochet hook and watching a pile of yarn slowly transform into something warm, colorful, and full of heart. The Rainbow Edged Granny Blanket is one of those projects that captures everything we love about crochet — the rhythm of working granny squares, the satisfaction of joining them together, and the pure joy of finishing it all off with a sweeping rainbow border that makes the whole piece sing. Whether you are a seasoned crocheter or someone who learned granny squares years ago and is looking for a fresh reason to revisit them, this free pattern has everything you need.
This blanket is made entirely with a classic granny square construction, then joined and finished with a bold, multicolored edge that gives it its name. The result is a cheerful, versatile throw that works beautifully in a nursery, draped over a living room sofa, or gifted to someone who deserves something handmade and full of color. Best of all, it is completely free to use, share, and make as many times as you like.
Let’s get into every detail so you can start your project with confidence.
About This Pattern
The Rainbow Edged Granny Blanket is designed to be approachable for beginners while still offering enough creative variation to keep more experienced crocheters engaged. The body of the blanket is composed of classic three-round granny squares worked in a neutral or coordinated color palette, and the magic really happens when you pick up a full spectrum of colors for the final border. You can make the squares as scrappy and random as you like, or work them in a controlled palette — both approaches look stunning.
The finished blanket measures approximately 48 by 60 inches when made with the yarn weights and hook size described below, making it a generous lap blanket or a cozy throw. You can easily size it up or down by adjusting the number of squares you make and join.
Materials You Will Need
Before you begin, gather everything together so you can settle in and crochet without interruption.
For the yarn, you will need worsted weight yarn in your choice of colors. The granny square body of the blanket works beautifully with a mix of coordinating colors, and you will need approximately 800 yards total for the squares. For the rainbow border, you will need roughly 50 to 75 yards each of red, orange, yellow, green, blue, and violet. A smooth, consistent acrylic or acrylic blend yarn is a great choice here because it is easy to care for, widely available, and comes in an enormous range of colors. Cotton yarn is another lovely option if you prefer a more breathable fabric, though keep in mind it tends to be slightly less stretchy than acrylic and may feel a little different to work with.
You will also need a size 5.0 mm (H/8) crochet hook, though you should always crochet a gauge swatch and adjust your hook size if needed. A yarn needle for weaving in ends, scissors, and stitch markers to keep track of your joining seams round out your supply list. Blocking mats and pins are optional but highly recommended — a light blocking after finishing transforms the blanket and makes every square lie perfectly flat.
Gauge
One granny square measures approximately 4 inches by 4 inches after blocking with the recommended yarn and hook. For a blanket approximately 48 by 60 inches, you will make 120 squares arranged in a grid of 10 squares wide and 12 squares tall. Gauge is not critical for a blanket, but staying consistent within your own work will ensure your squares are uniform and join neatly.
Abbreviations Used in This Pattern
ch — chain
sl st — slip stitch
sc — single crochet
dc — double crochet
sp — space
rep — repeat
st — stitch
RS — right side
WS — wrong side
The Granny Square Pattern
Each square is worked in the round, starting from a center ring and building outward. The classic three-round granny square is one of the most iconic motifs in crochet, and there is a reason it has endured for generations — it is fast, satisfying, and endlessly customizable.
Round 1: Make a magic ring or ch 4 and join with a sl st to form a ring. Ch 3 (counts as first dc), work 2 dc into the ring, ch 2. (Work 3 dc into the ring, ch 2) 3 times. Join with a sl st to the top of the beginning ch 3. You will have four clusters of 3 dc separated by ch-2 corner spaces. Fasten off if you are changing colors for round 2, or continue.
Round 2: Join new yarn in any ch-2 corner space. Ch 3 (counts as first dc), work 2 dc in the same space, ch 1. In the next ch-2 corner space, work (3 dc, ch 2, 3 dc), ch 1. Rep from the beginning of this instruction around all four corners, ending with 3 dc in the starting corner, ch 2. Join with a sl st to the top of the beginning ch 3. Fasten off or continue.
Round 3: Join yarn in any ch-2 corner space. Ch 3, work 2 dc in the same space, ch 1. Work 3 dc in the ch-1 side space, ch 1. In the next ch-2 corner, work (3 dc, ch 2, 3 dc), ch 1. Work 3 dc in the ch-1 side space, ch 1. Rep around. Join with sl st to top of beginning ch 3. Fasten off and weave in ends.
That’s your complete granny square. Make 120 of these, or however many you need for your desired blanket size.
Color Suggestions for the Squares
One of the most delightful things about a granny blanket is the freedom you have with color. Here are a few approaches that work beautifully with the rainbow edge.
A neutral body in shades of cream, white, and gray creates a soft, contemporary backdrop that lets the rainbow border be the undisputed star of the show. You can use a single neutral for all three rounds, or alternate between two or three neutrals across your squares for gentle variation.
A rainbow body where each square or each round uses a different color from the spectrum creates a riot of color that pairs beautifully with a crisp white or black rainbow border. This approach is ideal for using up scraps.
A tonal approach, where you pick one or two main colors and let the rainbow border complement them, gives the blanket a more curated, modern feel. Think deep teal squares with a warm rainbow border, or dusty rose squares edged in bold, saturated colors.
There is truly no wrong answer here. Crochet is deeply personal, and your color choices are what will make this blanket yours.
Joining the Squares
Once all your squares are made and ends are woven in, it is time to join them. There are several methods you can use, and each creates a slightly different look.
The flat slip stitch join, also called the join-as-you-go slip stitch, creates a raised ridge on the right side of the blanket that gives it a textured, handmade look. To do this, hold two squares with wrong sides together and work a slip stitch through the back loops of both squares along the edge. This method is fast and adds a lovely visual element.
The single crochet join works similarly but creates a more pronounced ridge. It adds a tiny bit of bulk at the seams, which some crocheters love and others prefer to avoid — try a small sample to see which you prefer.
The flat mattress stitch sewn join uses your yarn needle to whip stitch or mattress stitch squares together with the right sides facing. This creates an almost invisible seam on the right side and a tidy join on the back.
Whichever method you choose, take your time and keep your tension consistent. Nothing is more satisfying than a beautifully joined granny blanket laid out flat before the border goes on.
Lay your squares out in your 10 by 12 grid before you start joining, and take a photo for reference. Arrange them so the colors and patterns are distributed in a way that pleases you — this is worth spending a few minutes on because it makes a real difference in the final result.
Join in rows first, connecting all squares in each horizontal row, then join the rows to each other. This makes the process feel manageable and keeps your work organized.
The Rainbow Edge
This is where the blanket transforms from a lovely patchwork piece into something truly spectacular. The rainbow border is worked in six rounds, each in a different color of the rainbow. You can use the standard Roy G. Biv order (red, orange, yellow, green, blue, violet) or rearrange the colors to suit your palette.
Before beginning the border, work one full round of single crochet around the entire blanket in a neutral color (white, cream, or gray works well). This evens out any inconsistencies from the joining and creates a clean, smooth foundation for the rainbow rounds. Work sc stitches evenly across each side, working 3 sc into each corner st to keep the corners flat and square.
Round 1 of Rainbow Border (Red): Join red yarn at any corner. Ch 1, work sc in each stitch around, working 3 sc into each corner stitch. Join with sl st. Fasten off.
Round 2 (Orange): Join orange yarn at any corner. Ch 1, work sc in each stitch around, working 3 sc into each corner st. Join with sl st. Fasten off.
Round 3 (Yellow): Join yellow yarn at any corner. Ch 1, work sc in each stitch around, working 3 sc into each corner st. Join with sl st. Fasten off.
Round 4 (Green): Join green yarn at any corner. Ch 1, work sc in each stitch around, working 3 sc into each corner st. Join with sl st. Fasten off.
Round 5 (Blue): Join blue yarn at any corner. Ch 1, work sc in each stitch around, working 3 sc into each corner st. Join with sl st. Fasten off.
Round 6 (Violet): Join violet yarn at any corner. Ch 1, work sc in each stitch around, working 3 sc into each corner st. Join with sl st. Fasten off.
Weave in all remaining ends thoroughly. The rainbow border is complete.
If you want a bolder, chunkier border, you can work two rounds in each color instead of one. This gives you twelve rounds total and a wider, more dramatic rainbow frame. Both versions are beautiful — it simply depends on how statement-making you want the edge to be.
Finishing and Blocking
Weaving in ends is one of those tasks that crocheters either find meditative or deeply tedious, but it is worth doing properly. Use your yarn needle to weave each tail in at least two directions through the back of your work before trimming. This ensures the ends stay secure through washing and use.
Blocking the finished blanket makes a tremendous difference in how the fabric looks and feels. For acrylic yarn, wet blocking or steam blocking (with care) helps the stitches relax and the blanket lie flat. For cotton, wet blocking is the preferred method. Soak the blanket in cool water until it is saturated, then gently squeeze out excess water without wringing. Lay it flat on your blocking mats, pin it to the correct dimensions, and allow it to dry completely. This can take 24 to 48 hours depending on humidity and airflow.
Once blocked and dry, your Rainbow Edged Granny Blanket is ready to use, gift, or display.
Care Instructions
To keep your blanket looking its best for years to come, wash it on a gentle cycle in cool water and lay it flat to dry. Avoid high heat in the dryer, especially for acrylic yarn, as heat can distort the fibers. If your blanket is made with cotton, it can generally tolerate a slightly warmer wash, but always check your yarn label for specific guidance.
Tips for Success
Take your time with gauge. Even small inconsistencies in square size can compound over 120 squares, so if your first few squares seem too large or too small, adjust your hook before continuing.
Keep a consistent tension throughout. If you tend to crochet tightly when you start a project and loosen up as you go, try to be mindful of this and aim for the most consistent tension you can manage.
Use stitch markers liberally when working the border. Marking the corner stitches before each round ensures you always know where to work your three sc increases, which keeps the corners crisp and flat.
Don’t skip the foundation round before the rainbow border. That single round of neutral sc is doing real work, and skipping it can make the rainbow rounds look uneven.
Make it a project you enjoy over time. This blanket is not a quick weekend make — it is a satisfying long-term project you can pick up and put down over weeks or months. That is part of its beauty.
Ways to Customize This Blanket
The basic pattern is a wonderful jumping-off point for all kinds of personalization. You can make miniature versions as baby blankets by working fewer squares — a 6 by 8 arrangement with a single-round rainbow border makes a sweet and compact crib blanket. You can also work larger squares (adding more rounds to each motif) for a chunkier, more textured look.
Try a ripple or shell stitch border instead of single crochet for a more decorative rainbow edge. A shell stitch border in rainbow colors gives the blanket a ruffled, vintage feel that looks especially lovely in baby or nursery settings. A simple picot border in rainbow colors adds a delicate, lacy touch that works beautifully for a more refined, heirloom-style throw.
You can also vary the square style itself. The classic three-round granny works for nearly every aesthetic, but a solid granny (where you work continuous dc rows without the chain-one spaces) gives a denser, warmer fabric. Granny squares with a flower or popcorn center add dimension and visual interest.
A Note on Making This Blanket as a Gift
A handmade crochet blanket is one of the most meaningful gifts you can give. It represents hours of thought, effort, and care that no store-bought item can replicate. If you are making the Rainbow Edged Granny Blanket as a gift, consider the recipient’s color preferences and home decor when choosing your square colors, and let the rainbow border be the universal element that works with any palette.
Including a small tag or card explaining the yarn content and care instructions is a thoughtful touch that ensures the recipient can keep their blanket in great condition for years.
Final Thoughts
The Rainbow Edged Granny Blanket is more than just a crochet project. It is a reminder of why so many of us fell in love with this craft in the first place — the way simple stitches build into something bigger, the pleasure of choosing colors that make us happy, the meditative rhythm of working round after round. The granny square has been part of crochet tradition for generations, and adding that joyful rainbow border gives a beloved classic a fresh, modern energy.
Whether this is your first granny blanket or your fiftieth, we hope this free pattern brings you hours of enjoyment and results in a finished piece you are genuinely proud of. Share your finished blankets in your favorite crochet communities, tag your projects so others can find inspiration, and don’t hesitate to put your own creative spin on every element of this design.
Happy crocheting.
