After my kids and I sprouted seeds to see what the process entailed, we decided to carry out a series of seed experiments to learn more about seeds. Our seed experiments were designed to answer questions about what kinds of conditions seeds grow best in.
In this third seed experiment, we addressed the question: “Do seeds need air to grow?“
Note: For more seed activities your kids will love, see my Botany Unit Study page.
For any experiment, it is important to set up conditions so that the only difference between the conditions is related to what you want to test. Because we wanted to test how seeds grow with and without access to air, it was important that all of the growing conditions for our seeds be the same EXCEPT for their access to air.
We started with two plastic cups. We filled the “no air” cup about 1/3 full of water, but no dirt. We filled the “air” cup about 1/3 full with dirt and a bit of water. To both cups we added three different seeds: a broccoli seed, a lettuce seed, and a pea seed. (The seeds were part of this set of heirloom seeds I purchased.)
We then placed both cups on our kitchen window sill for about a week to see how the seeds would grow. I added water as needed to the “air” cup to ensure it remained moist. I did not add any water to the “no air” cup.
After a week we checked our seeds to see how they had grown. In the “air” cup (on the right in the picture below), all three seeds had started sprouting. The pea seed had put out a little shoot, while the broccoli and lettuce seeds had begun forming leaves. (It is a bit difficult to see in the picture since the broccoli leaves are covering the lettuce leaves).
In the “no air” cup, all three seeds appeared to have started spouting, but then had stopped growing. They never formed nice, big leaves like the seeds in the “air” cup. In fact, the tiny leaves that began forming separated from their seed, which would have prevented them from continuing to grow.
So after conducting this experiment, how would we answer our question “Do seeds need air to grow?”
We learned that the answer was yes. The seeds in both cups softened and began to sprout. But only the seeds with access to air continued to grow and form leaves. The seeds in the “no air” cup stalled in their growth, indicating that without air they will not thrive.
More resources for learning about seeds
More posts about seeds from Gift of Curiosity:
- Books about seeds
- Exploring seeds from packets
- Exploring seeds from nature
- Sprouting seeds
- Seed medallions craft
- Experiment: Do seeds need light to grow?
- Experiment: What temperature do seeds like?
- Experiment: Do seeds need their seed coat?
- Experiment: What liquids do seeds like?