Why does a plant need water?

When you forget to water a plant, its leaves go soft and droopy. Give it a drink and soon it stands up tall again. Water is doing some very busy jobs inside!

A drink from the roots up

A plant cannot walk to a tap, so it drinks through its roots in the soil. The water travels up the stem like juice up a straw, and spreads out to every single leaf. The whole plant gets a sip, from bottom to top.

Water keeps it standing tall

Each tiny part of a plant is like a little water balloon. When the parts are full of water, they are firm and the plant stands up straight and strong. When the water runs low, the balloons go floppy — and that is why a thirsty plant droops.

Water helps make food

Here is the most amazing job. A plant makes its own food using water, sunlight and air all mixed together inside the leaves. We call this photosynthesis. Without water, the plant could not cook its meals, and it would grow hungry and weak.

So water is a plant’s drink, its strong skeleton and part of its kitchen — all at once!

Wonder fact: A tall tree can drink hundreds of litres of water on a hot day — enough to fill a whole bathtub, sucked silently all the way up to the topmost leaves.