09/08/2026
It's that time of year again! Pumpkin Jack returns!
If your learners love getting a little gross with science, this is such a fun fall experiment! Pair the book Pumpkin Jack with a hands-on decomposition experiment and let your kids watch the science unfold right before their eyes. Start with a small *carved* pumpkin, some soil, and a container or terrarium. Then make a prediction:
What do you think will happen to Pumpkin Jack over the next few weeks?
Each week, observe Jack and have your learners:
- Draw what they see
- Look for changes in color, texture, mold, and size
- Record their observations
- Compare what actually happened to their original hypothesis
As Jack decomposes, kids can learn about bacteria, fungi, insects, microorganisms, decomposition, nutrient cycling, and how nature recycles organic matter back into the soil.
And the best part? There’s no need to rush the experiment. Letting kids observe the changes over time turns a simple pumpkin into a weeks-long science investigation.
It's messy. It's fascinating. And yes… its GROSS!
We put together the full Pumpkin Jack decomposition experiment, including setup ideas, questions to explore, and observation activities, in this blog: https://www.raisingbrain.org/single-post/fred-the-decomposing-jack-o-lantern-a-fun-fall-class-project