This is our cress caterpillar. You can see in the photo that 3 of the segments are a lighter shade of green than the other three. Can you guess why this might be?
How to grow a cress caterpillar
- cress seeds
- an egg box, cut into segments
- water
Cress Caterpillar Instructions
- Place some cress seeds in each segment of the egg box.
- Place three segments on one plate or tray and three on another plate or tray.
- Add water to all, and place one plate on a windowsill and one in the dark.
- Water frequently.
The cress should grow within a few days. I gave my ‘in the dark seeds’ a little light to help them grow, which is why they are slightly green.
Why are the cress leaves green?
I was very surprised that the seeds grew so well without any soil. They got everything they needed to grow from the water and nutrients stored in the seed.
Green plants make sugar for growth through a process called photosynthesis.
Carbon dioxide + water (and light ) ———> glucose and oxygen
Photosynthesis takes place in chloroplast cells, which contain a substance called chlorophyll which makes plants green.
Sunlight is also needed to make chlorophyll; this is why the cress seeds exposed to less sunlight are less green than those kept in the sun.
More plant and seed science for kids
Make an edible butterfly life cycle; use our free template to make it easy!

Dissect a flower to learn about the different parts.

Grow a bean in a jar!

Find out about leaf transpiration with Teach Beside Me.

Last Updated on March 26, 2023 by Emma Vanstone
this is totally cute! I love how you made a science project into a toy!
ooh this is so cute. I need to find where to get cress seeds, I’m so going to make this. x
How cute this one caterpillar I’ll eat, lol
I’d like to invite you to share this with our readers for Fun Stuff Friday @Toys In The Dryer http://www.toysinthedryer.com/2012/03/fun-stuff-fridays-16.html.
Done!
What are cress seeds? Watercress?
Its just garden cress, I think its related to watercress though . 🙂
I must do this with mine great caterpiller!
Thanks xx
Lovely idea! and tasty as well! love the way you’ve started teaching them science – never too young!!
Great 🙂
These are seriously cool- I love a fun way to get my littles interested in science. Very nice.
I love your caterpillar, it is sooo cute!
Thanks for sharing on Kids Get Crafty!
Maggy & Alissa
Oh my, this is absolutely lovely! Thanks for linking up to Kids Coop.
What a great lesson!! Thank you for sharing at Sharing Saturday! I hope you will share again this week with us!
Cute little caterpillar! And, of course, I love the science in it. 🙂
This is adorable! Thank you for linking this up with Tuesday Tots! I am featuring this this upcoming Tuesday 🙂
oh thank you 🙂