This blog post may contain affiliate links.
Thursday, September 16, 2021

16 Pumpkin Science Experiments & STEM Activities for Kids

Take advantage of all the pumpkins at fall time with these pumpkin science experiments and stem activities. Pumpkins aren't just for carving into the jack-o-lanterns, they're also really fun to decorate, explode, dissolve and disembowel. These experiments will explore chemical reactions, density and elasticity while delighting the senses.

pumpkin science reaction

If your kids love pumpkins and science experiments, they'll have heaps of fun exploring pumpkin guts, exploding and oozing substances out of pumpkins and creating pumpkins out of different materials. These experiments and activities are all great to do at home with preschoolers and school kids, or as a display at a science fair.


If you want to make pumpkins explode or watch things explode or ooze out of them then these science experiments are exactly what you're looking for! The experiments all bring chemical reactions to life, some in big ways and others on a smaller scale. Some of them will need to be done by adults or with adult help for safety.

Pumpkin Volcano

pumpkin volcano with baking soda and vinegar

Make a pumpkin volcano using a small pumpkin, dish soap, baking soda and vinegar. This experiment is easy enough to do on a tray in the classroom or at home. Will the force of the explosion pop off the pumpkin stalk, or will it bubble out the sides? You'll have to try it to find out. Follow the instructions at Steamsational.

Breathing Pumpkin

dry ice pumpkin

Create an eerie experience with this dry ice breathing pumpkin. This experiment needs dry ice so it definitely needs an adult help to set it up, however once the foggy breathe starts blowing out of the pumpkins mouth kids will be able to explore it. Follow the instructions at Preschool Powol Packets.

Pumpkin Geyser

pumpkin geyser

To create a truly explosive pumpkin, try this exploding pumpkin geyser. Be warned though this one is very quick and very intense and should be done by an adult as a demonstration for kids, rather than by kids themselves. It would be a spectacular display at a science fair! Follow the directions at Our Family Code to recreate this experiment. This one definitely needs to be done outside.

Puking Pumpkin

puking pumpkin experiment

Impress the kids with a puking pumpkin! After you've carved a jack-o-lantern bring it to life with some baking soda and vinegar and watch it puke everywhere. Follow the directions at Steam Powered Family and make sure this one is done outside to avoid a huge mess.

Elephant Toothpaste Pumpkin

elephant toothpaste pumpkin

Another fun oozing pumpkin experiment is an elephant toothpaste pumpkin. The jack-o-lantern will come to life and ooze out thick fluffy elephant toothpaste from it's eyes, nose, mouth and even it's head! Follow the directions at Hello Wonderful and you can see this experiment in action on YouTube here.

Oozing Ghost Pumpkins

exploding pumpkin ghosts

Create oozing ghost pumpkins with this fun experiment. You'll need a white pumpkin {which I've never actually seen in Australia}, baking soda, vinegar and dish soap. Follow the directions at Little Bins For Little Hands and make sure you do this one in a tray or outside.

Mini Bubbling Pumpkins

fizzing exploding pumpkins science activity

To made a more subdued pumpkin volcano try these mini fizzing pumpkins. This experiment is essentially the classic bicarb and vinegar experiment done inside hallowed out pumpkins. Follow the instructions at Natural Beach Living.

Fizzing Pumpkins

fizzing pumpkins experiment

Another fun pumpkin experiment is fizzing pumpkins. For this experiment you'll need to create magic pumpkins {we used a jack-o-lantern mould}, then you can watch them fizz and disappear. Follow our fizzing pumpkins experiment instructions to make them at home.


For more pumpkin science fun try these pumpkin slime recipes. Slime is a non Newtonian fluid so the feel and consistency changes as you stretch, mould and squish it in your hands. Slime is a great way to combine a sensory experience and science activity together. There's also lots of Halloween themed slime recipes here.

Pumpkin Slime

pumpkin slime recipe

The kids will have so much fun with this pumpkin slime. You'll need some Elmer's glue, liquid starch and some orange food colouring. Follow the recipe instructions at The Craft Train

Pumpkin Guts Slime

pumpkin slime with pumpkin seeds

It doesn't get much more pumpkin than this pumpkin slime made with real pumpkin guts inside a pumpkin! This is also a liquid starch based slime but has a different consistency due to the stringy pumpkin guts and slimy seeds. Follow the recipe at Little Bins For Little Hands


If exploding and oozing pumpkins or squishy pumpkin slime don't take your fancy then try some of these other interesting pumpkin experiments. Learn about the parts of a pumpkin, how to grow pumpkin crystals and how to make pumpkins magically appear.

Pumpkin Density Jar

parts of a pumpkin density experiment

Did you know the insides of a pumpkin have different density? In this pumpkin density experiment you can explore the different density of pumpkin flesh, guts, seeds and stems. Follow the directions at Steamsational.

Pumpkin Mystery Box

whats inside the pumpkin experiment

For another fun sensory science experiment try this what's inside the pumpkin experiment. Turn your pumpkins into a mystery touch and feel box by filling them with a sensory base and other objects. See what Science Sparks used for their experiment here.

Crystal Pumpkins

crystallised pumpkins

Make some crystallised pumpkins with this pumpkin crystal science experiment from Little Bins For Little Hands. Instead of using real pumpkins you'll need to make some out of pipe cleaners and use a supersaturated borax solution to grow crystals. 

Pumpkin Skittles Experiment

skittles pumpkin science ex

One of my kids favourite science experiments is the skittles rainbow and you can easily adapt that experiment to make a skittles pumpkin. The kids will love watching a pumpkin appear like magic, and they can still eat the skittles after! Follow the instructions at Active Littles to make your own.

Magic Pumpkin

This magic pumpkin experiment by Playdough to Plato is essentially the same as above but using Reese's pieces. You could also use Nestle Smarties. I wouldn't eat the watery chocolate candy afterwards though like you can with Skittles as I imagine it wouldn't taste very nice.

Melted Crayon Pumpkin

melted crayon pumpkin

Another fun way to use pumpkins is to make melted crayon pumpkin art. This will require some adult assistance as the pumpkin needs to be heated in the oven and will get quite hot. Follow the directions here to create your own artistic pumpkins.

pumpkin science experiments and stem activities for kids

Disclosure - This post contains some affiliate links for your convenience, which means I may earn a small commission at no cost to you, should you make a purchase.

Would you like to comment?