Pumpkin Science Activities for Preschool: Hands-On Investigations, Experiments & Pumpkin Jack

Pumpkin week gives us so many opportunities for real science in preschool. Instead of only talking about pumpkins or completing themed worksheets, we get to touch them, open them, make predictions, test ideas, observe changes, and even watch new plants begin to grow.

These pumpkin science activities for preschool give children hands-on ways to practice observation, prediction, comparison, vocabulary, and early scientific thinking. Best of all, most of the activities use simple materials and naturally fit into the kinds of conversations preschoolers are already having.

Pumpkin Science Activities for Preschool Start With Observation

Before we cut into a pumpkin or begin an experiment, we spend time simply looking at it.

The children use magnifying glasses to investigate the outside of the pumpkin and describe what they notice. We talk about its color, shape, size, stem, ribs, and texture. Children run their hands over the surface and compare what they see and feel.

This is also a great time to introduce vocabulary naturally. Instead of memorizing words from a picture card, children are able to connect words like stem, skin, ribs, smooth, rough, firm, and round to something they are actually touching.

I also ask questions that encourage children to think rather than simply give me an answer.

“What do you notice?”

“How does it feel?”

“Do you think all pumpkins look exactly the same?”

“What do you think is inside?”

Their answers give us a starting point for the rest of our investigation.

What Is Inside a Pumpkin?

Once we have investigated the outside, we open the pumpkin and find out what is actually inside.

The children examine the seeds, pulp, flesh, skin, and stem. Magnifying glasses come back out, and this time there is even more to investigate.

We compare the textures we find and talk about words like wet, slippery, stringy, smooth, sticky, hard, and soft.

This is one of those preschool activities where science and language development happen at the same time. Children have a real reason to describe what they see and feel because everyone is looking at the same interesting object.

Before opening the pumpkin, we can also make predictions about what we think we will find. Afterward, we revisit those predictions and compare them with what we actually observe.

The goal is not to make the “right” prediction. The important part is helping children understand that scientists make a prediction, test an idea, and then look at what actually happens.

Will a Pumpkin Sink or Float?

Once children have spent some time examining a pumpkin, we use it for another question:

Will a pumpkin sink or float?

Before putting it into the water, everyone makes a prediction.

Pumpkins feel heavy, so this activity usually creates some good discussion. Some children are completely convinced that something so heavy has to sink. Then we test it!

Afterward, we compare the result with our predictions and talk about what we notice. You can also extend this activity by testing smaller pumpkins, pumpkin pieces, seeds, the stem, or other fall objects.

Again, I try not to turn this into a lesson where I explain everything before the children have a chance to think. The prediction and observation are the important parts.

What Will Dissolve the Candy Pumpkin?

Our next pumpkin experiment uses candy pumpkins and three different liquids: water, lemon-lime soda, and oil.

Before placing the candy pumpkins into the cups, the children make predictions about what they think will happen.

Will the candy pumpkin dissolve?

Will it stay the same?

Will one liquid change it faster than another?

We leave the pumpkins in the liquids and observe them over time. Then we compare the cups and talk about the changes we see.

This is a simple experiment, but it gives children practice with several important science skills at once: predicting, observing, comparing, and noticing change over time.

It also gives us some great vocabulary opportunities as we talk about dissolving, liquids, changes, faster, slower, same, and different.

If you take another photo later in the experiment showing the pumpkins after they have begun changing, I’d include that directly underneath this one. A before-and-after pair would work really well here.

Watching a Pumpkin Change... and Grow!

One of our longer pumpkin science investigations begins with Pumpkin Jack by Will Hubbell.

After reading the story, we place a carved pumpkin inside a clear container with soil and observe what happens over time.

This experiment does not give us an instant result, which is part of what makes it valuable.

The children continue checking the pumpkin long after the original investigation ends. We notice changes in its shape, color, texture, and appearance and talk about what is happening as the pumpkin decomposes.

I like asking simple observation questions:

“What looks different today?”

“What do you notice?”

“Is the pumpkin changing quickly or slowly?”

“What do you think might happen next?”

Children begin to see that some scientific changes happen immediately, while others take days, weeks, or even longer.

Planting Pumpkin Seeds for a Faster Look at Growth

Because Pumpkin Jack takes time, we also save a few seeds from our pumpkin and plant them separately in our classroom window box.

This gives children a quicker way to observe another part of the pumpkin life cycle.

We check the soil, make sure our seeds have what they need, and watch for the first signs of growth. When a sprout appears, the children are able to connect that tiny plant back to the seeds they found inside the pumpkin.

The two investigations work especially well together. Pumpkin Jack lets us watch an old pumpkin slowly break down, while our planted seeds let us watch new growth begin.

Together, they make the pumpkin life cycle much more concrete than simply looking at a diagram.

Pumpkin Pie in a Cup: A Sensory Science Experience

Science does not always have to happen at the science table! In fact, one of our favorite pumpkin experiences is making pumpkin pie in a cup!

We use pumpkin pie filling, graham crackers, and whipped cream to create a simple preschool-friendly version of pumpkin pie.

First, the children place graham crackers into a bag and use small mallets to crush them into crumbs for the crust. That step is always fun, but it also gives children a chance to notice how a material changes when force is applied. Whole crackers become smaller pieces and eventually crumbs.

Then we layer the graham cracker crumbs and pumpkin filling into cups and top everything with whipped cream.

As we make the cups, we talk about the ingredients, textures, smells, and changes we notice.

The graham crackers go from whole to crushed. The ingredients are layered in a particular order. The textures feel and look different from one another.

Children are also practicing sequencing as they follow the steps from beginning to end.

And, of course, tasting the finished product gives us one more sense to add to the investigation.

Pumpkin Science Does Not Need to Be Complicated

Some of the best preschool science happens when we give children something interesting and then give them time to look closely.

A pumpkin already gives us almost everything we need. We can observe it, describe it, open it, compare its parts, make predictions, test whether it floats, watch something dissolve, plant its seeds, and observe decomposition over time.

None of these experiences require children to memorize a list of facts. Instead, they get to ask questions and see what happens.

That is what I want science to look like in preschool: hands-on, curious, a little messy, and connected to something children can actually experience.

If you are planning your own pumpkin week, these investigations pair naturally with pumpkin life cycle activities, vocabulary, counting, measuring, and observation activities.

And there are plenty more pumpkin ideas happening in our classroom, too!