A cluster of treble crochet stitches is when you work three treble crochet stitches into the same stitch. However, if you just did this the normal way it wouldn't be a cluster stitch; it would just be three trebles in the same stitch. To make it a cluster crochet stitch, you need to leave off the final step of each treble until the very end, when you close the treble all at once. That's what makes it a cluster; you'll have three side-by-side treble crochet stitches that all end at the top in one stitch.
Cluster crochet stitches are textured stitches, like bobbles and popcorn stitches, that pop out slightly from the fabric and create a plush design.
Note that this is different from a triple treble crochet stitch, which is a single crochet stitch (not three side-by-side) that is taller than a regular treble crochet stitch.
Here are some abbreviations that are used in the instructions below:
st = stitch
sts = stitches
tr = treble
Reminder: A treble crochet stitch is worked by wrapping the yarn or thread around the hook two times before inserting the hook into the stitch where it is going to be worked. (See how to do a treble crochet stitch if you need a refresher on the basics.)
How to crochet a 3 tr cluster stitch:
You are going to be making the treble crochet cluster stitch with the same process that you use to make a regular treble crochet. The only difference is going to be that you're not going to complete the final step of a regular treble crochet.
You will leave the last loops on the hook and then begin the next treble crochet. Likewise, you will leave that one unfinished and begin the final treble of the cluster. When all three treble crochet stitches are the same height, you will close them all together so that the three stitches become one cluster stitch.
Here is how you do it:
1. Wrap yarn or thread around hook 2 times. (Note, that if you wanted to make a double crochet cluster instead of a treble, you would start with one yarn over. Just a reminder to give you a frame of reference.)
2. Insert your crochet hook into the stitch where you want the cluster. This is typically dictated by your crochet pattern. In some cases it will simply be into the next available stitch. That's what you will see in the photo that accompanies this article, which depicts a 3 tr crochet cluster in between sets of regular treble crochet stitches.
3. Draw up a loop.
4. Wrap yarn over hook and draw through two of the loops that are on the crochet hook. There will now be three hook remaining on the loop. This should all be familiar since we are still just working a regular treble crochet stitch.
5. Yarn over hook and draw through two loops again. There will be two loops left on the hook. Now we are going to pause at this stage of the first treble and we are going to begin the next treble crochet.
6. Working in the same stitch, make a second treble (leave the last loop of this treble on the hook also). In other words, repeat steps 1-5. When you finish step 5 this second time around, there will be three loops left on the hook instead of just two.
7.Working in the same stitch, make the third treble (leave the last loop of this treble on the hook also). So again, you are going to repeat steps 1-5 but this time there are going to be four loops left on the hook at the end of the repeat.
8. Now you have three unfinished treble crochet stitches sitting side-by-side inside the same stitch. All you need to do is close them up. To do this, wrap yarn over hook and pull a loop through all four remaining loops on the hook. This closes all three trebles into one treble crochet cluster.