Photosynthesis KS2

Looking for a simple way to teach photosynthesis in KS2? This guide explains what photosynthesis is, why it is important and how it is taught in Key Stage 2. You'll also find practical teaching ideas and a ready-to-teach lesson pack to help children understand this essential Science topic.

Photosynthesis is one of the key concepts children learn about plants in KS2. By exploring how plants make their own food using sunlight, water and carbon dioxide, children begin to understand how living things depend on one another and why plants are vital for life on Earth.

Need a lesson on photosynthesis? 

Our ready-to-teach KS2 photosynthesis lesson explores the process by which plants make their own food from sunlight in a clear, age-appropriate way. It includes: 

  • a detailed lesson plan 
  • teaching slides
  • differentiated activity ideas
  • printable resources 

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What is Photosynthesis?

Photosynthesis is the process plants use to make their own food. Green plants absorb energy from sunlight and use it to combine water from the soil with carbon dioxide from the air. This produces glucose, which the plant uses for energy and growth, while oxygen is released into the atmosphere.

Children don't usually need to memorise the chemical equation in primary school, but they should understand the basic idea that:

  • plants need sunlight
  • plants take in water through their roots
  • plants absorb carbon dioxide through their leaves
  • plants produce glucose for food
  • plants release oxygen into the air
Diagram showing the process of photosynthesis for KS2 pupils
Diagram showing the process of photosynthesis for KS2, including sunlight, water, carbon dioxide, glucose (sugar) and oxygen

Why is Photosynthesis Important?

Without photosynthesis, life on Earth would not exist as we know it. Plants provide food for almost every food chain and produce the oxygen that humans and animals need to survive.

Learning about photosynthesis also helps children understand:

  • why plants need light to grow
  • how plants are different from animals
  • how food chains begin with plants
  • the importance of forests and green spaces
  • how plants help remove carbon dioxide from the atmosphere

Photosynthesis in the KS2 National Curriculum

Photosynthesis is introduced during Upper Key Stage 2 as part of the Science curriculum. Pupils learn how plants make their own food and investigate the role of water, carbon dioxide and light in this process.

Before studying photosynthesis, children build their understanding of plants by learning about:

  • parts of flowering plants
  • plant growth
  • life cycles
  • seed dispersal
  • how water is transported within plants

This prior knowledge helps pupils understand why leaves, roots and stems all play an important role in photosynthesis.

How to Explain Photosynthesis to KS2 Children

A helpful way to introduce photosynthesis is to compare plants with people.

Humans eat food to get energy, but plants cannot walk to the kitchen or buy food from a shop. Instead, they make their own food using sunlight.

You could explain it like this:

Plants are like tiny food factories. Their leaves collect sunlight, their roots absorb water and their leaves take in carbon dioxide from the air. Using all three ingredients, the plant makes glucose, which gives it the energy it needs to grow.

Simple diagrams, animations and practical investigations all help make this abstract process easier for children to understand.

Fun Ways to Teach Photosynthesis KS2

  • Label the different parts of a plant involved in photosynthesis.
  • Create a diagram showing the journey of sunlight, water and carbon dioxide through the plant.
  • Investigate what happens when plants are kept in light and dark conditions.
  • Use role play, with children acting as sunlight, water and carbon dioxide.
  • Make flow charts explaining each stage of the process.
  • Discuss how photosynthesis links to food chains and ecosystems.

Common Misconceptions About Photosynthesis

Children often think:

  • plants get their food from the soil (they actually make it themselves)
  • plants only need water to survive
  • oxygen is taken in during photosynthesis (it is released)
  • plants only photosynthesise during the summer

Addressing these misconceptions early helps pupils develop a secure understanding of plant biology.

Teach Photosynthesis with Ready-to-Use Lessons

If you're teaching photosynthesis in KS2, our ready-to-teach lesson pack contains everything you need to deliver engaging Science lessons with confidence.

The resource includes detailed lesson plans, differentiated activities, presentation slides, worksheets and assessment opportunities to help children understand how plants make their own food through photosynthesis.

👉 Explore the ready-to-teach photosynthesis lesson

More KS2 Science Resources

If you're teaching plants, you may also find these resources useful:

Frequently Asked Questions

What is photosynthesis in KS2?

Photosynthesis is the process by which green plants use sunlight, water and carbon dioxide to make glucose (food). Oxygen is produced as a by-product and released into the air.

What year is photosynthesis taught?

Photosynthesis is taught in Year 3 as part of the Primary Science National Curriculum, although younger children develop the knowledge needed to understand the process through earlier learning about plants.

How do you explain photosynthesis to children?

A simple explanation is that plants make their own food. They use sunlight as energy to combine water from the soil with carbon dioxide from the air, producing glucose to help them grow.

Why do children learn about photosynthesis?

Learning about photosynthesis helps children understand how plants grow, why plants are essential for life on Earth and how living things depend on one another within ecosystems.