Plants Don't See Light... They Feel It

Plants have special light-detecting cells inside their leaves and stems.

These cells don't form pictures like our eyes do, but they can tell which direction the brightest light is coming from.

As soon as a young shoot detects light on one side, it begins preparing to change direction.

It's almost like the plant is saying,

"The sunlight is over there... I'd better grow that way!"

The Secret Is Hidden Inside the Stem

The real magic happens inside the growing stem.

Plants make a tiny chemical messenger called auxin.

When light shines from one side, auxin moves to the shaded side of the stem.

The cells on the shaded side grow a little longer than the cells on the sunny side.

Because one side grows faster than the other, the whole stem slowly bends towards the light.

Scientists call this amazing response phototropism.

Why Is Finding Light So Important?

Plants don't grow towards light just because they "like" sunshine.

They need light to make their own food through photosynthesis.

The more sunlight they can collect, the more energy they have to grow new leaves, flowers and seeds.

For tiny seedlings growing beneath larger plants, finding even a small patch of sunlight can make the difference between surviving and dying.

That's why growing towards light is one of the most important survival skills a plant can have.

Essy's Plant Detective Challenge

Your Egg-head found the light on a sunny windowsill...

But what would happen if the only light was red?

Or blue?

Would it still know which way to grow?

Real plant scientists ask these extra questions because every investigation uncovers another mystery waiting to be solved.

Somewhere in a rainforest, a forest floor or even your own backyard, thousands of tiny seedlings are quietly searching for the light... just like your Egg-head did.