5 little pumpkins sitting on a gate! Except these 5 little pumpkins are actually a pumpkin crystal science experiment. What a fun fall or Halloween science activity to pair with a classic book. Growing crystals with kids is really easy to do whether you do salt crystals with construction paper or the classic borax crystals with pipe cleaners, it’s a great chemistry activity for kids. Combine classic science experiments with fun themes kids love!


Easy to set up pumpkin crystal science experiment growing borax crystals with kids! Pair this pumpkin themed science activity with a classic book like 5 lLittle Pumpkins Sitting On A Gate! Growing crystals is awesome kid science you can do at home or in the classroom. Fall science, pumpkin science, crystal growing science for preschool, kindergarten, and early elementary age kids.
So what happens when 5 little pumpkins sit on a gate? They turn into crystal pumpkins! Last year we actually crystalized a real mini pumpkin, check it out here. This year, a pipe cleaner pumpkin crystal science experiment was in order!

This year we made a twist on the classic pipe cleaner crystal growing activity by twisting our pipe cleaners into the shape of pumpkins. Abstract pumpkins if you will. I am sure you could get a bit fancier and create spheres like this 3D beaded pumpkin pipe cleaner craft.

Growing crystals is a fun science activity that you can also turn into a science experiment. We will show you how to do that below! Let’s get started. Make sure to grab a copy of this classic book for the younger kids!


Amazon affiliate links included for convenience.

Orange Pipe Cleaners

Green/Brown Pipe Cleaners

Borax Powder




Glass Jars {Wide Mouth Mason Jars Work Best}

Measuring Cups

Skewers or Pencils

Pumpkin crystal science experiment growing crystals with borax powder and pipe cleaners


Start out by twisting the orange pipe cleaners into pumpkin shapes. We used one whole pipe cleaner per pumpkin. You can squish them around a bit to be longer or rounder as you please. Each one will definitely be unique!

We added a long green pipe cleaner stem which also serves as a way to suspend the pumpkins in the solution. You could also do brown and add leaves or make a curly vine! So many options for creativity that it also makes for a great craft project for the craftier scientist. Basic works too!

Wrap the stems around a skewer or pencil. Try not to touch the sides or bottom as they will be difficult to remove. You could also use string if you find you need to lower them farther down into the solution.

Mix up your solution! This is where the science comes into the activity because you have the opportunity to learn about mixtures and saturated solutions!

CHECK IT OUT: All of our Fall Science and STEM ideas!

Mixing up borax solution for pumpkin crystal science experiment


The ratio of borax to water is 3 tablespoons to 1 cup, so you can determine how much you need. This experiment to make 5 crystal pumpkins required 4 cups and 12 tablespoons divided between the containers.

You want hot water. I bring the water to just boiling. Measure the correct amount of water and stir in the correct amount of borax powder. It will not dissolve. It will be cloudy. This is what you want, a saturated solution. Optimal crystal growing conditions!

You can read more on crystal growing but lets start with the basics. What you made in the beginning of the project is called a saturated solution.

pipe cleaners suspended in borax crystal growing solution

The borax has been suspended throughout the solution and remains that way while the liquid is hot. A hot liquid will hold more borax than a cold liquid! The molecules in hot water are much farther away from each other than in cold water allowing the water to hold more of the borax solution.

As the solution cools, the molecules return closer to each other and the particles settle out of the saturated mixture. The settling particles form the crystals that you see. The impurities remain behind in the water and cube like crystals will form if the process of cooling is slow enough.

If the solution cools to quickly, irregular shaped crystals will form due to the impurities that got caught in the process.

LET IT REST UNDISTURBED for 24 hours but make sure to observe the changes you see taking place. Remove from the solution and let dry on a paper towel.

Saturated Solutions with borax crystal growing activity and pumpkin crystal science experiment


Covered vs Uncovered

Fo this particular experiment we chose to cover one of the jars with tin foil to slow down the cooling process. We found a heavier amount of crystallization on that glass container than the uncovered one.

I think had we used a mason jar {which we usually us}, we would have had even better results! The opening on a mason jar is not as big as the opening on these 2 cup measurers.

We didn’t get an awesome shot of the differences between the two but they were noticeable, so I will pass the challenge along to you!

Plastic Container vs. Glass Container

You can see the difference with this experiment here.

Using a plastic cup versus the glass jar caused a difference in the formation of the crystals. As a result, the glass jar crystals are more heavy duty, larger, and cube shaped.

While the plastic cup crystals are smaller and more irregularly shaped. Much more fragile too. The plastic cup cooled off more quickly and crystal pipe cleaners contained more impurities than those in the glass jar.

5 Little Pumpkin Crystal Science Experiment Activity

Our pumpkin crystal science experiment doubles as a terrific pumpkin science craft the kids will find fascinating. Who doesn’t want to grow their own crystals?

Crystal Pumpkin Science Experiment for Fall STEM Activities


You might also like these awesome pumpkin themed activities to try with your kids. Click on the photos!


  1. The pumpkin crystal experiment is amazing! Can’t wait to try it with my son… He’ll love it. Thanks for linking to our beaded pumpkin craft!

Comments are closed.