Changing Colour Flowers with Transpiration!

So you have some white flowers but actually wouldn’t they look good with a bit of red in them? Or maybe blue? Not only are they pretty but can be used to demonstrate transpiration.

Coloured carnation

How could you do this? Well with what looks like a little bit of magic and a huge dollop of science!

Get your lovely white flowers – carnations are a good one to use! (Obviously mummy’s I do these flower experiments for you too!)

Strangely celery also works really well!

Changing colour flowers Science sparks

Place your celery into the food dye in water

Trim them at the stalks

Get your vase and fill with water – add some food colouring of your choice.

Place in your flowers and wait.

Usually you can see effects within a few hours!

Be generous with the food dye!

coloured carnation

This one is yellow and black!

The science bit

The reason this happens is because of something called the transpiration stream. This is the movement of water up the stem of a plant from root to leaf when water is lost from the plant due to evaporation occurring at the leaves. Firstly water is absorbed by the root and moves through root hair cells via the process of osmosis (we will look at this another day!). It then moves into the xylem vessel which is the tube that carries the water up the plant. Plants are not like us with pumping mechanism that pushes our blood around, so water moves up the vessel by adhesion (being attracted to the side of the vessel) and cohesion (water molecules being attracted to each other). Therefore when water evaporates from the top of the leaves it changes the pressure in the vessel and pulls up the column of water to replace the water lost.

The best way to consider this is to imagine you have a thick shake – the straw can’t carry the shake up it, but if you suck from the top, you change the pressure and force the shake up the straw. It moves in a column because the molecules are attracted to each other.



Author: Emma Vanstone

Science Sparks, is a site dedicated to making Science fun for kids. I’d love you to follow me on my Google Profile+.

Share This Post On


    • Thank you so much. We will stop by. If you have craft posts yourself come and link to our fun sparks on a Thursday! :)

      Post a Reply
  1. I did this for my kids this summer. We used daisy’s…it didn’t work. I have done it with carnations before and it worked, but not sure why daisy’s didn’t work!

    Post a Reply
    • I think the stem structure can vary somewhat and only certain flowers work effectively. Definitely try carnations next time!

      Post a Reply
    • We are all linked up so thank you! A beautiful sea or turquoise if ever I saw!

      Post a Reply
  2. Thanks for the tip! I’m going to try this one out!

    Post a Reply
    • It is great! x

      Post a Reply
  3. Yet another fabulous experiment to explore with children! I remember always wanting to try this but never getting round to it.. I WILL with my kids! ;-)

    Thank you for liking to Kids Get Crafty!


    Post a Reply
    • Thanks Maggy

      Post a Reply
  4. You have so many great ideas on your blog. I would love if you would link some of them up to my Weekend Wonders blog hop!

    Post a Reply
    • Is that a Sat or a Sunday? Can you send us the link, as that would be great! Thanks for stopping by, we are so pleased you like it! :)

      Post a Reply
  5. I don’t know of a child that doesn’t find this utterly fascinating! It’s such a great idea! I have to have a go at this with Little One!

    Thank you for linking up to #handmadethursday x

    Post a Reply
    • Thank you kindly! Let us know if you do have a go! :) x

      Post a Reply
  6. What a great experiment! Will definitely be giving this one a go! Well done girls, another simple but fun experiement my children will love.

    Post a Reply
    • Thank you lovely! x

      Post a Reply
  7. I love this experiment – it works really well in the spring as well with Daffodiles we always used to have multi coloured daffs in the house in spring.

    Post a Reply
    • Thank you! We will definitely have a go with daffodils in the spring.

      Post a Reply
  8. Just stopping by to let you know that I have featured your project on Fun Family Crafts! You can see it here

    If you have other kid friendly crafts, I’d love it if you would submit them :) If you would like to display a featured button on your site, you can grab one from the right side bar of your post above.

    Post a Reply
  9. I remember doing these as a kid with my grandmother – so fun! Thanks for reminding me to do them with my own kids!

    Post a Reply
    • oh wow! Thats great. It is a really fab experiment! x

      Post a Reply
  10. How long does it take for you to see the change in color?

    Post a Reply
    • Usually by the end of the day!

      Post a Reply
  11. Wondering…If I dye 6 carnations, seperately, a different color each (like the colors of the rainbow), could I then combine them in one vase of plain water after the petals have changed color?

    Post a Reply
  12. Hi I tried this but it didn’t work I used a white flower or should I wait longer.

    Post a Reply
    • Make wait longer, or make your coloured solution stronger. Good luck.

      Post a Reply


  1. Color Experiments – An It’s Playtime Round Up - [...] Science Sparks changes the colors of flowers in a recent science experiment. [...]
  2. Science Sparks » Happy New Year and a Blog Hop - [...] favourite post from last year has to be Kerry’s post on transpiration. It is so simple yet gives a …
  3. Close up! « Multiple Mummy - [...] the colour of flowers! Transpiration in [...]
  4. Science for kids - science play | Science Sparks - [...] is for transpiration –  make some pretty flowers or coloured [...]
  5. Science for kids - Valentine Science ideas | Science Sparks - [...] How about making some pretty flowers? [...]
  6. St Patricks Day Kids Activities - [...] green food coloring and white carnations to make St. Patrick’s Day Flowers with this simple and fun science [...]
  7. Springtime Nature Trail Challenge - Mummy..Mummy..Mum! - [...] favourite flower photo of all time is this one from Science Sparks, so my aim is to take a …
  8. Science magic | Science Sparks - [...] Bored of plain white petals? magically jazz them up with some food colouring to make these pretty flowers. [...]
  9. Water Science - […] could explore transpiration and make some pretty flowers. I LOVE this activity, if it works well, you can see …
  10. Christmas Flowers - Transpiration Activity - Science Sparks - […] done a few transpiration activities before, and if you followed our Spectacular Summer Science  series you might remember I …
  11. Science Activity Ideas for Valentine's Day - […] You could make some pretty flowers for your Valentine, with this transpiration experiment. […]
  12. Flower Craft ideas | Life surrounded by Blues - […] about the Science of Flowers – Changing Colour flowers with Transpiration – Science […]
  13. Why do plants need water? | Science Sparks - […] Transpiration is the process by which water moves up the stem of a plant from root to leaf when water …

Submit a Comment

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title="" rel=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

CommentLuv badge