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 in this easy colour changing flowers activity.
Transpiration for Kids
How to make colour changing flowers
You’ll need
White flowers
Food colouring – we’ve found Wilton gel colours work well. Natural food colourings DO NOT work in our experience.
Water
Small jar or vase
How to make colour changing flowers
Trim the flowers at the stalks.
Fill as vase or jar with water and add some food colouring of your choice.
Put your flowers in the water and wait.
Usually will see the flowers change colour within a few hours.
Extra Transpiration Challenge
Try carefully splitting a stem in half with a sharp knife ( ask an adult to do this )
Place one half of the stem in one colour water and the other in a different colour. After a few hours you should have a flower with different coloured petals!
What is Transpiration?
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.
What food colouring should I use?
We have found that natural food colours don’t work. These Wilton Gel Colours work for us every time.
If you liked this experiment don’t forget to try my other plant science experiments.
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Marilyn
September 26, 2011 at 7:11 pmSo lovely and creative :)) loving your blog and officially following with smiles per blog hop..I’m Marilyn via http://theartsygirlconnection.blogspot.com and I’d love for you to stop in sometime..off to indulge in your posts..:))
ScienceSparks
October 12, 2011 at 9:12 pmThank you so much. We will stop by. If you have craft posts yourself come and link to our fun sparks on a Thursday! 🙂
Melissa
September 26, 2011 at 8:55 pmI 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!
ScienceSparks
October 12, 2011 at 9:13 pmI think the stem structure can vary somewhat and only certain flowers work effectively. Definitely try carnations next time!
Sara
September 27, 2011 at 9:22 pmSo cute!! Would LOVE it if you would link this up at my turquoise lovin’ party going on right now!! http://www.sweetlittlegals.com/2011/09/turquoise-lovin-6.html
ScienceSparks
October 12, 2011 at 9:17 pmWe are all linked up so thank you! A beautiful sea or turquoise if ever I saw!
Janae
September 28, 2011 at 8:50 amThanks for the tip! I’m going to try this one out!
ScienceSparks
September 29, 2011 at 6:12 pmIt is great! x
maggy, red ted art
September 28, 2011 at 1:32 pmYet 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!
Maggy
ScienceSparks
September 29, 2011 at 6:12 pmThanks Maggy
mum of all trades
September 30, 2011 at 9:47 pmYou 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!
ScienceSparks
October 12, 2011 at 9:18 pmIs 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! 🙂
mummiafelice
October 1, 2011 at 6:52 amI 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
ScienceSparks
October 12, 2011 at 9:19 pmThank you kindly! Let us know if you do have a go! 🙂 x
Fiona @Coombemill
October 3, 2011 at 9:43 pmWhat a great experiment! Will definitely be giving this one a go! Well done girls, another simple but fun experiement my children will love.
ScienceSparks
October 12, 2011 at 9:18 pmThank you lovely! x
Rainy Day Mum
October 4, 2011 at 11:02 amI 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.
ScienceSparks
October 4, 2011 at 12:33 pmThank you! We will definitely have a go with daffodils in the spring.
creativejewishmom/sara
October 6, 2011 at 8:42 pmthanks so much for sharing on Craft Schooling Sunday!
Amanda
November 20, 2011 at 2:09 pmJust stopping by to let you know that I have featured your project on Fun Family Crafts! You can see it here
http://funfamilycrafts.com/changing-color-flowers/
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.
Mama Pea Pod
January 2, 2012 at 4:44 pmI remember doing these as a kid with my grandmother – so fun! Thanks for reminding me to do them with my own kids!
ScienceSparks
January 2, 2012 at 7:55 pmoh wow! Thats great. It is a really fab experiment! x
Kathy
January 9, 2012 at 9:39 pmHow long does it take for you to see the change in color?
ScienceSparks
January 9, 2012 at 10:54 pmUsually by the end of the day!
Christy
March 12, 2012 at 6:28 amWondering…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?
Sonia
November 5, 2012 at 1:03 amHi I tried this but it didn’t work I used a white flower or should I wait longer.
ScienceSparks
November 5, 2012 at 8:39 amMake wait longer, or make your coloured solution stronger. Good luck.
Pinkoddy
January 30, 2014 at 9:23 pmThis is really interesting – am sure my boys would really love this.
Sthuthukile Ngcobo
April 17, 2018 at 9:56 amIt is a very colourful science topic and also interesting to play around with it