Hi everyone!

A few weeks ago, Squeaks and I set up a really cool experiment: we planted some seeds to see how they would grow! Do you remember how we set up the experiment?

We put seeds in four cups. Then, we gave the seeds in one cup everything a plant needs to grow: sunlight, water, and soil. But the seeds in the second cup didn’t get sunlight, the seeds in the third didn’t get water, and the seeds in the last cup had sand instead of soil.

Something happened after we set up our experiment: Squeaks and I found out that we made a mistake! One of our groups of seeds wasn’t supposed to get any sunlight, but we planted them in a clear cup! Even though we covered the top of the cup, plenty of light came in through the sides.

So to fix our mistake, we started the experiment over, and this time we put the seeds that weren’t supposed to get sunlight in a dark cabinet. Then, we let our plants grow for three weeks. And now let’s take a closer look at what happened.

The grass that got sunlight, water, and good soil grew really well! How does that compare to what we thought would happen? Looking back at my plant journal, Squeaks and I thought that the plant with everything it needed — sunlight, water, and soil — would grow the best.

And we were right! The seeds that didn’t get any water didn’t grow at all, which also matches what we thought would happen. And the seeds we planted in sand instead of soil grew a little bit, so we were right about that too!

But look at the grass that didn’t get any sunlight. We thought it would only grow a little bit, but it actually grew a lot, and then it died. And if you look at the color of the grass, you can see that it was a very light yellow instead of green.

So our results were a little different from what we thought would happen, but that’s okay! That’s what experiments are for — to test our ideas and see what happens. We were really surprised that the grass that didn’t get any sunlight grew so much.

Plants need sunlight to make their food, and we didn’t think the seeds would be able to grow very much without any food. We wanted to know why the grass grew a lot, and why it was so yellow, so we looked it up! We learned that when you put a plant in the dark, it grows a lot to try and reach the light it needs to make its food and stay alive.

If the plant grows tall enough, it might be able to get past whatever’s blocking the light and start making food again. So that’s why the grass we kept in the dark grew so much — it was looking for light. But since the grass was in a dark cabinet, it would never reach any light no matter how much it grew.

Without light, the grass couldn’t make more food, so it slowly died. So even though it grew at first, the grass couldn’t survive in the dark. The dark cabinet was also the reason the grass was yellow instead of green.

Plants are green because they have a chemical called chlorophyll inside them, which captures sunlight and helps turn it into energy. But when there isn’t any light for the chlorophyll to use, it goes away. So the grass was light yellow because it was missing chlorophyll.

Even though our results were different than we expected, we learned a lot from our experiment! We showed that plants need sunlight, water, and good soil to survive. I bet we could learn even more about how plants grow by trying this experiment again, but changing what we give each group of seeds.

For example, we could give all the plants sunlight, but give each plant a different amount of water. Or we could try watering one of the plants with saltwater! There are lots of ways to learn more about how to grow a healthy plant.

So keep experimenting! Thanks for joining us on SciShow Kids, and we’d like to give Google Making Science a big thank you for helping us make this episode! Did you try this experiment, and want to show us your results?

Just grab a grown-up to leave a comment down below, or send us an e-mail to kids@scishow.com. And we’ll see you next time, here at the fort!