Here's a good experiment for the very small people who are in lockdown at the moment, anyone can do this one and enjoy it!
This experiment is an oldey but a goody, and lets you talk to the kids about how plants work. We all know plants need water to grow, but how do they move water around? Well - all plants have a specialised network of tiny vessels running through them. There are two types of vessels, one called Xylem, and one called Phloem. Broadly (and simplifying things for the kids) the Xylem vessels move the water from the roots to the leaves and the Phloem moves the "sap" (sugar and nutrients). Luckily for us, its very easy to find these vessels in some everyday plants - like Celery!
We had some limp old celery sitting in the bottom of the fridge, and it worked fine for this. Don't feel you need the fresh stuff.
Step 1: Take a few celery stalks, chop off a couple of centimetres from the ends and a small amount from the top. Then pick some nice bright colours and put a few drops of food colouring into a glass of water. Pop the celery in... and wait.
We left ours overnight to get a really bright colour - but it should work in half an hour or so.
The celery sticks will start taking up some of the water through the Xylem vessels. These are the stringy bits on the edge of the celery, they're actually tiny tubes through which the celery transports its water. As the coloured water rises up the Xylem, some will be released into the tissue surrounding it, so the celery itself will change colour slightly.
By peeling back the top of the celery and pulling the stringy vessels down, you'll see they are full of the coloured water. And that's how you find the tiny tubes that plants use to move water from the soil to the leaves. If you cut small sections from the celery stalk, you'll see a row of the Xylem tubes along the outside of the