You Will Need:
Small clear container
Potting compost (optional)
Plants are pretty good at making lots more of themselves - and not just from seeds. In fact they can quite often grow new roots from a tiny snipped off stem which is a bit like growing a new pair of feet out of a tiny finger - except much less weird.
Usually this clever work goes on under the ground but some plants will let you peek at what they do because they'll even produce new roots in water. If you want to watch the magic in action, first you'll need to find some suitable plants to snip. Many herbs are good to try such as rosemary, mint, sage, tarragon, lemon balm, thyme and oregano.
Cut about 15cm from the end of a plant stem without flowers, strip off any leaves on the bottom half and then place this 'cutting' in a small container of water on a sunny windowsill. It's good to find a container with a slightly narrower top as this will help hold the stem upright.
You should change the water every few days so it stays fresh - you can use tap water but rainwater is even better as it contains less chemicals and more nutrients.
Amazingly within 2-6 weeks (depending on the plant) you should start to see roots begin to grow out of the base of the stem. You can keep them this way, harvesting their new leaves if they are herbs, or else carefully plant them in small pots of compost and try growing them on.
Tip: Unlike leaves, roots prefer to grow away from light so you could use darker glass containers or even wrap some paper around the container.
If you haven't caused enough mayhem yet:
Why not try taking other leaf, root or stem cuttings from different plants and see how many you can grow. Which do better - those in water or those in potting compost? Why do you think this is?
The Sciencey Bit
Roots which grow from somewhere other than the original seed or from the main root itself are called adventitious roots. When plants are grown from other parts of a plant such as a stem, leaf or root cutting this is called vegetative propagation and results in the plants being genetically identical to their parents