Plants: what do they need to grow?
What plants need, what roots, stems and leaves do, and why plants grow towards the light. With a grow-a-seed experiment.
Read
Animals have to eat to get food. Plants are different: they make their own food. They need light, water and air to do it.[2]
The roots grow down into the soil and drink up water. The stem carries the water up to the leaves.[3][4]
The leaves are the plant's kitchen. They catch sunlight and use it to make food. Leaves are green because of a green colour inside them called chlorophyll.[1][2]
Plants turn and grow towards the light. Put a plant on a windowsill and after a few days it leans to the window![4]
Plants also give out oxygen, the part of the air that we need to breathe. And animals eat plants, so almost all food starts with a plant.[1][2]
Try it: Seeds in the light and in the dark
You need
- Cress seeds (or broad bean seeds)
- Two small pots or yoghurt pots with cotton wool or soil
- Water
- A cupboard or a box with a lid
- A sunny windowsill
Safety
Wash hands after touching soil. Do not eat seeds bought for planting. Mop up spilled water so nobody slips.
What to do
- Put damp cotton wool (or soil) in both pots and sprinkle the same number of seeds on each.
- Put one pot on a sunny windowsill and the other in a dark cupboard.
- Give both pots the same small amount of water every day so they stay damp.
- Look every day. Which pot grows faster? What colour are the leaves? Which way do the stems lean?
- Draw both pots after one week.
Play: Plant or animal?
Read each card. Does it describe a plant or an animal? Pick the right box.
Your best score is kept only on this device. Nothing is sent anywhere.
Quiz
Other ages: Ages 10–11 · Ages 15–16