[♪ INTRO]
[Squeaks squeaks]
That’s a really good question, Squeaks!
You might know that Squeaks and I have been planning a garden near the Fort.
We’re going to grow some amazing veggies to eat.
Like radishes, beans, and…
[Squeaks squeaks]
Yeah, and tomatoes too.
And we’ve learned that plants need two important things
to help them grow: water and light.
They also need somewhere to grow.
But Squeaks came up with a really great question:
all of our plants grow in dirt, or soil.
How come that’s not one of the things a plant needs to grow?
Well, to answer that, let’s start by talking about
why most plants we see every day grow in soil.
From small plants like grass, to big plants like trees, they all grow in soil!
Plants like these have roots.
Most roots grow into the ground.
And roots have a lot of jobs.
One job that most roots do is to act like an anchor,
and hold the plant in place so it doesn’t get blown away by the wind.
Roots also help to hold the plant upright.
This helps hold the plant steady as leaves stretch toward the sunlight!
Roots also help the plant to get water.
When we water plants, we usually pour water on the soil.
The water trickles down through the soil to the roots,
and that’s how it gets into the plant.
It’s absorbed, or taken up, by the root.
Water isn’t the only thing that gets absorbed by the root.
Often there are nutrients in the soil.
Nutrients are things like vitamins and minerals
that help the plant grow and stay healthy.
Just like vitamins and minerals help people grow and stay healthy.
The nutrients get mixed into the water, and get taken into the plant too.
[Squeaks squeaks]
Yes!
It is possible for a plant to grow without soil.
Healthy soil is a wonderful place for roots to grow.
But if there’s another way to get plants the water and nutrients they need,
then the plant wouldn’t really need soil,
as long as it was growing in a place where it was safe and secure.
And we can set up a pretty simple experiment to demonstrate how!
What do you think, Squeaks?
[Squeaks squeaks]
Let’s make a plan!
First, we’ll need some seeds.
Not all plants will work well with this experiment,
but I’ve read that lettuce seeds grow pretty well this way.
The seeds should already be starting to grow just a little bit when we set them up.
I sprouted these lettuce seeds in a sealed plastic bag with a wet paper towel,
just like Junper showed us with those beans, remember?
[Squeaks squeaks]
Look, here’s a teeny tiny leaf, and a teeny tiny root!
They’re on a piece of cotton so they stay in place.
Now, let’s think of everything we know that plants need
Light, water, and nutrients.
I’ve got water right here.
The nutrients, in this case plant food, are mixed into the water, so we can’t see them.
Now, we need some kind of container…
[Squeaks squeaks]
Oh good idea, an empty plastic bottle from the recycling bin
will work very well.
And we need one more thing.
We’ll use this aquarium pump to blow air into the water and nutrients.
That will keep everything mixed up so the growing plants get everything they need.
Okay, let’s put everything together!
We need to carefully cut the top off of the bottle.
Then we’ll turn it over, and fit it into the bottom part of the bottle.
And let’s mark a line right here
so that we can see how high we need to fill the bottom part.
We’ll make a little hole above that line and push the tube of the aquarium pump
through the hole so it will go down into the water and nutrients.
We’ll fill up the bottom part and then carefully put our cotton with the seeds on it
so that their baby roots will get wet.
And put it near a window to make sure the plants get plenty of light…
Turn on the pump… And now we wait!
[Squeaks squeaks]
Well, we’ll have to wait a couple of weeks at least.
It takes time for plants to grow.
Over this time we’ll need to make sure that the bottom part of the setup
stays full of water and nutrients.
We’ll just have to check back in about four to six weeks,
to show everyone how they grew!
[Squeaks squeaks]
Another great question!
Squeaks wants to know: Why would you grow plants this way,
if they grow in soil just fine?
Well, there are some plants in nature that don’t grow in soil.
For example, these plants grow in the tops of rainforest trees.
Their roots attach right on the tree’s branch or trunk.
Way up high like that they get plenty of sun,
and they get the water they need from the damp rainforest air.
Their roots also take in nutrients they need from stuff that collects on tree’s branches.
Cool, right?
People might also need to grow plants this way if they don't have access to soil.
In many cities, for example, there’s no room for a big farm.
But there are lots of people who need to eat vegetables.
And something similar is even used in space on the International Space Station!
It can help astronauts grow fresh food
even though the soil of the Earth is way below them!
But for now, growing all this lettuce
is making me think of the salad I brought for lunch.
Are you ready to eat, Squeaks?
[Squeaks squeaks]
Thanks for joining us today.
If you want to keep learning and having fun with Squeaks, me,
and all of our other friends, be sure to hit the subscribe button,
and we'll see you next time here at The Fort!
[Squeaks squeaks]
[♪ OUTRO]